greybus: Remove "gb-" prefix from .c files

Some files are still prefixed with "gb-" with the reasoning that the modules
would be named so, i.e.  gb-*.ko. But this can be done by playing a bit in
Makefile instead and keep uniform naming of .c files.

Lets try it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/Makefile

@@ -17,6 +17,12 @@ gb-phy-y :=	gpb.o		\
 		i2c.o	\
 		usb.o
 
+# Prefix all modules with gb-
+gb-vibrator-y := vibrator.o
+gb-battery-y := battery.o
+gb-es1-y := es1.o
+gb-es2-y := es2.o
+
 obj-m += greybus.o
 obj-m += gb-phy.o
 obj-m += gb-vibrator.o