build: remove stale .ipk files if package dir changes

If a package nonshared status is changed, a stale .ipk file might still
be present in the old package directory. Remove the .ipk file from all
package directories when building a new one (or explicitly running
clean)

Signed-off-by: Felix Fietkau <nbd@nbd.name>

include/rootfs.mk

@@ -45,10 +45,6 @@ opkg = \
 	--add-arch all:100 \
 	--add-arch $(if $(ARCH_PACKAGES),$(ARCH_PACKAGES),$(BOARD)):200
 
-opkg_package_files = $(wildcard \
-	$(foreach dir,$(PACKAGE_SUBDIRS), \
-	  $(foreach pkg,$(1), $(dir)/$(pkg)_*.ipk)))
-
 TARGET_DIR_ORIG := $(TARGET_ROOTFS_DIR)/root.orig-$(BOARD)
 
 define prepare_rootfs