i915/display/dmc: Add Support for PipeC and PipeD DMC

So far we had support for main, PipeA and PipeB
DMC. If we find a binary from PipeA-D, lets load it.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211006204547.669464-1-anusha.srivatsa@intel.com

drivers/gpu/drm/i915/display/intel_dmc.h

@@ -20,6 +20,8 @@ enum {
 	DMC_FW_MAIN = 0,
 	DMC_FW_PIPEA,
 	DMC_FW_PIPEB,
+	DMC_FW_PIPEC,
+	DMC_FW_PIPED,
 	DMC_FW_MAX
 };