[media] marvell-ccic: remove g_chip_ident

Remove g_chip_ident. This driver used some of the V4L2_IDENT defines, replace
those with a driver-specific enum. This makes it possible to drop the
v4l2-chip-ident.h define as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>