HID: Kconfig: split HID support and hid-core compilation

Currently, we step into drivers/hid/ based on the value of
CONFIG_HID.

However, that value is a tristate, meaning that it can be a module.

As per the documentation, if we jump into the subdirectory by
following an obj-m, we can not compile anything inside that
subdirectory in vmlinux. It is considered as a bug.

To make things more friendly to HID-BPF, split HID (the HID core
parameter) from HID_SUPPORT (do we want any kind of HID support in the
system?), and make this new config a boolean.

Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Benjamin Tissoires <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/Makefile

···
 obj-$(CONFIG_SUPERH)		+= sh/
 obj-y				+= clocksource/
 obj-$(CONFIG_DCA)		+= dca/
-obj-$(CONFIG_HID)		+= hid/
+obj-$(CONFIG_HID_SUPPORT)	+= hid/
 obj-$(CONFIG_PPC_PS3)		+= ps3/
 obj-$(CONFIG_OF)		+= of/
 obj-$(CONFIG_SSB)		+= ssb/

drivers/hid/Kconfig

···
 #
 # HID driver configuration
 #
-menu "HID support"
-     depends on INPUT
+menuconfig HID_SUPPORT
+	bool "HID bus support"
+	default y
+	depends on INPUT
+	help
+	  This option adds core support for human interface device (HID).
+	  You will also need drivers from the following menu to make use of it.
+
+if HID_SUPPORT
 
 config HID
-	tristate "HID bus support"
-	depends on INPUT
+	tristate "HID bus core support"
 	default y
 	help
 	  A human interface device (HID) is a type of computer device that
···
 
 source "drivers/hid/surface-hid/Kconfig"
 
-endmenu
+endif # HID_SUPPORT

drivers/hid/amd-sfh-hid/Kconfig

···
 menu "AMD SFH HID Support"
 	depends on X86_64 || COMPILE_TEST
 	depends on PCI
-	depends on HID
 
 config AMD_SFH_HID
 	tristate "AMD Sensor Fusion Hub"
+	select HID
 	help
 	  If you say yes to this option, support will be included for the
 	  AMD Sensor Fusion Hub.