rootfs: remove unnecessary and potentially harmful force flags from opkg call

Especially --force-overwrite and --force-depends will often lead to broken
images; it's better to fail the build in such cases than to silently ignore
the errors.

Instead, ignore errors in the per-device rootfs opkg remove command, so
the build doesn't break when packages can't be removed because of
dependencies.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

include/rootfs.mk

@@ -40,10 +40,7 @@ opkg = \
   TMPDIR=$(1)/tmp \
   $(STAGING_DIR_HOST)/bin/opkg \
 	--offline-root $(1) \
-	--force-depends \
-	--force-overwrite \
 	--force-postinstall \
-	--force-maintainer \
 	--add-dest root:/ \
 	--add-arch all:100 \
 	--add-arch $(if $(ARCH_PACKAGES),$(ARCH_PACKAGES),$(BOARD)):200