ar71xx: remove patches for 3.8 (leftover after r37315)

Signed-off-by: Luka Perkov <luka@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37324 3c298f89-4303-0410-b956-a3cf2f4a3e73
ar71xx: really delete patches-3.8 directory



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37325 3c298f89-4303-0410-b956-a3cf2f4a3e73