media: omap3isp: Enable driver compilation on ARM with COMPILE_TEST

The omap3isp driver can't be compiled on non-ARM platforms but has no
compile-time dependency on OMAP. It however requires common clock
framework support, which isn't provided by all ARM platforms.

Drop the OMAP dependency when COMPILE_TEST is set and add ARM and
COMMON_CLK dependencies.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>