scripts/feeds: force kernel package scan after a target installation

scripts/feeds: force kernel package scan after a target installation

When a target is installed from a feed, the linux kernel package is scanned
before the installation of this target.
If some kernel module packages are defined in this feeds at the target
level, there were not parsed during the scan of linux kernel package, as
the target didn't exist yet. So these kernel module packages don't exist.

Once the target is installed, clean the linux kernel packageinfo to force
the scan of the linux kernel package next time this script (or the make
command) is called.

Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Link: https://patchwork.ozlabs.org/project/openwrt/patch/mailman.117548.1727195440.1280.openwrt-devel@lists.openwrt.org/
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>