ar71xx: add kernel support for WD My Net N750

Signed-off-by: Felix Kaechele <heffer@fedoraproject.org>
[juhosg: use a separate patch for kernel changes]
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39077 3c298f89-4303-0410-b956-a3cf2f4a3e73
ar71xx: add userspace support for WD My Net N750

Signed-off-by: Felix Kaechele <heffer@fedoraproject.org>
[juhosg: remove the image generation part until the ethernet
         switch issue is resolved]
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39078 3c298f89-4303-0410-b956-a3cf2f4a3e73