[media] omap2: Fix camera resources for multiomap

Make sure the kernel can be compiled with both OMAP2 and OMAP3 camera
support linked in, and give public symbols proper omap2/omap3 prefixes.

Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>