media: atomisp: get rid of version-specific system_local.h

After removing the unused 32-bits data, the isp2401_system_local.h
now contains everything that it is needed, either by isp2401 or
by isp2400.

So, remove code duplication.

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