dm2q: Set correct PATCH_AVB path for boot image

mkboot/bootimg.mk

@@ -1,4 +1,4 @@
-PATCH_AVB:=device/samsung/sm8550-common/mkboot/avb_digest_patch.py
+PATCH_AVB:=device/samsung/dm2q/mkboot/avb_digest_patch.py
 
 FLASH_IMAGE_TARGET ?= $(PRODUCT_OUT)/recovery.tar