kernel: b53: allow access the MIB counters on BCM5365

b53_no_ops has no elements and b53_port_ops has one element, this makes 
the code access some random memory when trying to access the mib 
counter functions.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>


git-svn-id: svn://svn.openwrt.org/openwrt@37895 3c298f89-4303-0410-b956-a3cf2f4a3e73