media: atomisp: print css_version in runtime

The CSS version returned by ISP2400 is different than the one
returned by ISP2401.

While we could return just one version for both, as this sounds
like just an informative string, for now, let's keep returning
different versions, as we don't know if this would affect
userspace.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>