Android: Add driver "all" option to enable all drivers

Add a driver string "all" so that if BOARD_GPU_DRIVERS is set to "all",
all the drivers are enabled in the build. This makes build testing all
drivers easier to maintain.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
1 file changed