ion: drop dependency on ARM

Ion will compile and run on other platforms now, remove the
dependency on ARM.
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/Kconfig

 menuconfig ION
 	tristate "Ion Memory Manager"
-	depends on ARM
 	select GENERIC_ALLOCATOR
 	select DMA_SHARED_BUFFER
 	help