greybus: spi: Separate out spilib from spi bridged PHY bundle driver

spilib can be used by multiple bridge drivers implementing different
bundle classes. Separate out bridged PHY bundle drivers parts.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile
index a9802da..35fc6bf 100644
--- a/drivers/staging/greybus/Makefile
+++ b/drivers/staging/greybus/Makefile
@@ -40,6 +40,7 @@
 gb-gpio-y := gpio.o
 gb-i2c-y := i2c.o
 gb-usb-y := usb.o
+gb-spi-y := spi.o
 
 obj-m += greybus.o
 obj-m += gb-gpbridge.o
@@ -69,6 +70,7 @@
 obj-m += gb-gpio.o
 obj-m += gb-i2c.o
 obj-m += gb-usb.o
+obj-m += gb-spi.o
 
 KERNELVER		?= $(shell uname -r)
 KERNELDIR 		?= /lib/modules/$(KERNELVER)/build