media: atomisp: cleanup ifdefs from ia_css_debug.c

There are lots of code dependency there. Get rid of most of
them.

We can't remove everything, as there are some structs that
are conditionally built if ISP2401. So, keep ifdefs only
on such cases.

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