mb/starlabs/starfighter: Enable pmc_shared_sram device

Eliminates errors in cbmem

Change-Id: I1e9b02a0391b952eb461f174b3dc73783eed2853
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90282
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/starlabs/starfighter/variants/mtl/devicetree.cb

@@ -224,6 +224,7 @@ chip soc/intel/meteorlake
 				end
 			end
 		end
+		device ref pmc_shared_sram on  end
 		device ref i2c0		on
 			chip drivers/i2c/hid
 				register "generic.hid"		= ""STAR0001""