media: v4l: cci: Add macros to obtain register width and address

Add CCI_REG_WIDTH() macro to obtain register width in bits and similarly,
CCI_REG_WIDTH_BYTES() to obtain it in bytes.

Also add CCI_REG_ADDR() macro to obtain the address of a register.

Use both macros in v4l2-cci.c, too.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>