kmod: add patches to support build on RHEL 5

kmod uses certain features not available on older RHEL 5 machines (RedHat
Enterprise Linux). This commit adds two patches to fix that.

Both patches have been proposed upstream, the second one being accepted, the
first rejected with the suggestion to add the patch in Buildroot instead.

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>