kernel: fix arch-dependent bug in hso module

Currently, the module causes an oops at least on rt5350. These patches
have been accepted upstream at:
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git

Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>

git-svn-id: svn://svn.openwrt.org/openwrt@37931 3c298f89-4303-0410-b956-a3cf2f4a3e73