media: camss: Allocate power domain resources dynamically

To simplify the driver's maintenance it makes sense to escape from
hardcoded numbers of power domain resources per platform and statical
allocation of the resources. For instance on a QCOM SM8450 platform
the number of CAMSS power domains shall be bumped up to 6, also notably
CAMSS on MSM8916 has only one power domain, however it expects to get 2,
and thus it should result in a runtime error on driver probe.

The change fixes an issue mentioned above and gives more flexibility
to support more platforms in future.

Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>