Enable missed cache for local debs (#14794)

- Why I did it
To be able to cache, and then retrieve cached "copied" debs

- How I did it
Add missed caching and cache retrieval steps

- How to verify it
Build with cache and then clean and rebuild again. The targets added to SONIC_COPY_DEBS should be taken from a cache.

Signed-off-by: Yevhen Fastiuk <yfastiuk@nvidia.com>

slave.mk

@@ -544,10 +544,25 @@ endef
 #     SOME_NEW_DEB = some_new_deb.deb
 #     $(SOME_NEW_DEB)_PATH = path/to/some_new_deb.deb
 #     SONIC_COPY_DEBS += $(SOME_NEW_DEB)
-$(addprefix $(DEBS_PATH)/, $(SONIC_COPY_DEBS)) : $(DEBS_PATH)/% : .platform
+$(addprefix $(DEBS_PATH)/, $(SONIC_COPY_DEBS)) : $(DEBS_PATH)/% : .platform \
+	$(call dpkg_depend,$(DEBS_PATH)/%.dep)
+
 	$(HEADER)
-	$(foreach deb,$* $($*_DERIVED_DEBS), \
-	    { cp $($(deb)_PATH)/$(deb) $(DEBS_PATH)/ $(LOG) || exit 1 ; } ; )
+
+	# Load the target deb from DPKG cache
+	$(call LOAD_CACHE,$*,$@)
+
+	# Skip building the target if it is already loaded from cache
+	if [ -z '$($*_CACHE_LOADED)' ] ; then
+
+		$(foreach deb,$* $($*_DERIVED_DEBS), \
+			{ cp $($(deb)_PATH)/$(deb) $(DEBS_PATH)/ $(LOG) || exit 1 ; } ; )
+
+		# Save the target deb into DPKG cache
+		$(call SAVE_CACHE,$*,$@)
+
+	fi
+
 	$(FOOTER)