media: rkisp1: Add feature flags for BLS and compand

Add feature flags for the dedicated black level subtraction hardware
block and for the compand hardware block. The companding feature flag is
added on its own (as opposed to "the absence of BLS") because we will
need it later for when we add support for the companding block.

Skip BLS configuration when the BLS feature flag is unset, as devices
without the dedicated BLS block cannot configure a hardware block that
doesn't exist.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>