allow packages to override PKG_UNPACK, HOST_UNPACK

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@14659 3c298f89-4303-0410-b956-a3cf2f4a3e73

include/unpack.mk

@@ -67,10 +67,10 @@ ifeq ($(strip $(UNPACK_CMD)),)
 endif
 
 ifdef PKG_BUILD_DIR
-  PKG_UNPACK := $(call UNPACK_CMD,$(PKG_BUILD_DIR)) $(call CRLF_CMD,$(PKG_BUILD_DIR))
+  PKG_UNPACK ?= $(call UNPACK_CMD,$(PKG_BUILD_DIR)) $(call CRLF_CMD,$(PKG_BUILD_DIR))
 endif
 ifdef HOST_BUILD_DIR
-  HOST_UNPACK := $(call UNPACK_CMD,$(HOST_BUILD_DIR)) $(call CRLF_CMD,$(HOST_BUILD_DIR))
+  HOST_UNPACK ?= $(call UNPACK_CMD,$(HOST_BUILD_DIR)) $(call CRLF_CMD,$(HOST_BUILD_DIR))
 endif
 
 endif # PKG_SOURCE