media: atomisp: add return codes for pipeline config functions

Those functions can internally break, but, as they don't return
errors, internally there are some assert() calls, which is bad,
as it hangs the driver.

So, add return codes there, in preparation for removing such
assert() calls.

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

media: atomisp: propagate errors at ia_css_*_configure()

Propagate the lower lever ia_css config errors to the next
level.

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

media: atomisp: add SPDX headers

This driver is licensed under GPL 2.0, as stated inside their
headers.

Add the proper tag there. We should probably latter cleanup
the reduntant licensing text, but this could be done later,
after we get rid of other abstraction layers.

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

media: atomisp: drop a cast for a const argument

Some arguments for tnf and ref settings are meant to be const, but
they're defined without such annotation. Due to that, there's an
ugly cast at sh_css_sp.c.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: atomisp: cleanup directory hierarchy

This driver has very long directories without a good
reason (IMHO). Let's drop two directories from such hierarchy,
in order to simplify things a little bit and make the dir
output a bit more readable.

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