phase1: remove kmods in target packages if archive is enabled

OPKG gets confused if kmod packages are present in both, target packages
as well as kernel version specific folder.
Remove them from target packages to make opkg pick the kmods from kmod
archive folder only.

This also affects APK that picks packages from the first entry in the
repository file and doesn't support checking the same package from
multiple entry.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
[ add --remove-source-files and improve implementation ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>