[media] media: venus: enable building with COMPILE_TEST

We want all media drivers to build with COMPILE_TEST, as the
Coverity instance we use on Kernel works only for x86. Also,
our test workflow relies on it, in order to identify git
bisect breakages.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>