package/kmod: fix host install

The host directory no longer uses /usr.

This currently works because we still have the  legacy /usr
symlink, but for correctness it is better that we just fix it.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>