staging: android-alarm: Support old drivers via preprocessor aliasing

Older out of tree drivers that were desgined to the Android Alarm
in-kernel API may not build due to the namespace collision fixed in
an earlier patch. Per Arve's suggestion, this patch provides
preprocessor macros that allow older drivers to build.

CC: Arve Hjønnevåg <arve@android.com>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>