ralink: fix a regression that broke pcie on mt7621

i accidentally dropped 2 lines while adding mt7628 support

Signed-off-by: John Crispin <blogic@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@43216 3c298f89-4303-0410-b956-a3cf2f4a3e73