media: atomisp: remove format duplication at mbus->fourcc table

This table used to be used also to translate between ia_css
abstraction and V4L2 fourcc codes.

This was removed on a past patch, but the table now contains
two fields with identical values.

Get rid of one of them.

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