net: ethernet: ti: Remove TI_CPTS_MOD workaround

My recent commit b6d49cab44b5 ("net: Make PTP-specific drivers depend on
PTP_1588_CLOCK") exposes a missing dependency in defconfigs that select
TI_CPTS without selecting PTP_1588_CLOCK, leading to linker errors of the
form:

drivers/net/ethernet/ti/cpsw.o: in function `cpsw_ndo_stop':
cpsw.c:(.text+0x680): undefined reference to `cpts_unregister'
...

That's because TI_CPTS_MOD (which is the symbol gating the _compilation_ of
cpts.c) now depends on PTP_1588_CLOCK, and so is not enabled in these
configurations, but TI_CPTS (which is the symbol gating _calls_ to the cpts
functions) _is_ enabled. So we end up compiling calls to functions that
don't exist, resulting in the linker errors.

This patch fixes build errors and restores previous behavior by:
- ensure PTP_1588_CLOCK=y in TI specific configs and CPTS will be built
- remove TI_CPTS_MOD and, instead, add dependencies from CPTS in
TI_CPSW/TI_KEYSTONE_NETCP/TI_CPSW_SWITCHDEV as below:

config TI_CPSW_SWITCHDEV
...
depends on TI_CPTS || !TI_CPTS

which will ensure proper dependencies PTP_1588_CLOCK -> TI_CPTS ->
TI_CPSW/TI_KEYSTONE_NETCP/TI_CPSW_SWITCHDEV and build type selection.

Note. For NFS boot + CPTS all of above configs have to be built-in.

Cc: Arnd Bergmann <[e-mail]>
Cc: Dan Murphy <[e-mail]>
Cc: Tony Lindgren <[e-mail]>
Fixes: b6d49cab44b5 ("net: Make PTP-specific drivers depend on PTP_1588_CLOCK")
Reported-by: kbuild test robot <[e-mail]>
Signed-off-by: Clay McClure <[e-mail]>
[[e-mail]: rewording, add deps cpsw/netcp from cpts, drop IS_REACHABLE]
Signed-off-by: Grygorii Strashko <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Tested-by: Tony Lindgren <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/arm/configs/keystone_defconfig

···
 CONFIG_SPI=y
 CONFIG_SPI_DAVINCI=y
 CONFIG_SPI_SPIDEV=y
+CONFIG_PTP_1588_CLOCK=y
 CONFIG_PINCTRL_SINGLE=y
 CONFIG_GPIOLIB=y
 CONFIG_GPIO_SYSFS=y

arch/arm/configs/omap2plus_defconfig

···
 CONFIG_HSI=m
 CONFIG_OMAP_SSI=m
 CONFIG_SSI_PROTOCOL=m
+CONFIG_PTP_1588_CLOCK=y
 CONFIG_PINCTRL_SINGLE=y
 CONFIG_DEBUG_GPIO=y
 CONFIG_GPIO_SYSFS=y

drivers/net/ethernet/ti/Kconfig

···
 config TI_CPSW
 	tristate "TI CPSW Switch Support"
 	depends on ARCH_DAVINCI || ARCH_OMAP2PLUS || COMPILE_TEST
+	depends on TI_CPTS || !TI_CPTS
 	select TI_DAVINCI_MDIO
 	select MFD_SYSCON
 	select PAGE_POOL
···
 	tristate "TI CPSW Switch Support with switchdev"
 	depends on ARCH_DAVINCI || ARCH_OMAP2PLUS || COMPILE_TEST
 	depends on NET_SWITCHDEV
+	depends on TI_CPTS || !TI_CPTS
 	select PAGE_POOL
 	select TI_DAVINCI_MDIO
 	select MFD_SYSCON
···
 	  will be called cpsw_new.
 
 config TI_CPTS
-	bool "TI Common Platform Time Sync (CPTS) Support"
-	depends on TI_CPSW || TI_KEYSTONE_NETCP || TI_CPSW_SWITCHDEV || COMPILE_TEST
+	tristate "TI Common Platform Time Sync (CPTS) Support"
+	depends on ARCH_OMAP2PLUS || ARCH_KEYSTONE || COMPILE_TEST
 	depends on COMMON_CLK
-	depends on POSIX_TIMERS
+	depends on PTP_1588_CLOCK
 	---help---
 	  This driver supports the Common Platform Time Sync unit of
 	  the CPSW Ethernet Switch and Keystone 2 1g/10g Switch Subsystem.
 	  The unit can time stamp PTP UDP/IPv4 and Layer 2 packets, and the
 	  driver offers a PTP Hardware Clock.
-
-config TI_CPTS_MOD
-	tristate
-	depends on TI_CPTS
-	depends on PTP_1588_CLOCK
-	default y if TI_CPSW=y || TI_KEYSTONE_NETCP=y || TI_CPSW_SWITCHDEV=y
-	default m
 
 config TI_K3_AM65_CPSW_NUSS
 	tristate "TI K3 AM654x/J721E CPSW Ethernet driver"
···
 	select TI_DAVINCI_MDIO
 	depends on OF
 	depends on KEYSTONE_NAVIGATOR_DMA && KEYSTONE_NAVIGATOR_QMSS
+	depends on TI_CPTS || !TI_CPTS
 	---help---
 	  This driver supports TI's Keystone NETCP Core.
 

drivers/net/ethernet/ti/Makefile

···
 ti_davinci_emac-y := davinci_emac.o davinci_cpdma.o
 obj-$(CONFIG_TI_DAVINCI_MDIO) += davinci_mdio.o
 obj-$(CONFIG_TI_CPSW_PHY_SEL) += cpsw-phy-sel.o
-obj-$(CONFIG_TI_CPTS_MOD) += cpts.o
+obj-$(CONFIG_TI_CPTS) += cpts.o
 obj-$(CONFIG_TI_CPSW) += ti_cpsw.o
 ti_cpsw-y := cpsw.o davinci_cpdma.o cpsw_ale.o cpsw_priv.o cpsw_sl.o cpsw_ethtool.o
 obj-$(CONFIG_TI_CPSW_SWITCHDEV) += ti_cpsw_new.o