USB: move common alchemy USB routines to arch/mips/alchemy/common.c

A previous patch converted the Alchemy platform to use the OHCI and EHCI
platform drivers. As a result, all the common logic to handle USB present in
drivers/usb/host/alchemy-common.c has no reason to remain here, so we move it
to arch/mips/alchemy/common/usb.c which is a more appropriate place. This
change was suggested by Manuel Lauss.

Signed-off-by: Florian Fainelli <[e-mail]>
Acked-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

arch/mips/alchemy/common/Makefile

···
 #
 
 obj-y += prom.o time.o clocks.o platform.o power.o setup.o \
-	sleeper.o dma.o dbdma.o vss.o irq.o
+	sleeper.o dma.o dbdma.o vss.o irq.o usb.o
 
 # optional gpiolib support
 ifeq ($(CONFIG_ALCHEMY_GPIO_INDIRECT),)

drivers/usb/host/Makefile

···
 obj-$(CONFIG_USB_IMX21_HCD)	+= imx21-hcd.o
 obj-$(CONFIG_USB_FSL_MPH_DR_OF)	+= fsl-mph-dr-of.o
 obj-$(CONFIG_USB_OCTEON2_COMMON) += octeon2-common.o
-obj-$(CONFIG_MIPS_ALCHEMY)	+= alchemy-common.o
 obj-$(CONFIG_USB_HCD_BCMA)	+= bcma-hcd.o
 obj-$(CONFIG_USB_HCD_SSB)	+= ssb-hcd.o