Subject: [PATCH 1/1] config: sam9g25: add NAT support

support NAT to tether network interfaces

Signed-off-by: Royce Jiang <jiangxd@embedinfo.com>
sdimage: sam9g25ek: add android sdimage config for sam9g25ek

Signed-off-by: Royce Jiang <jiangxd@embedinfo.com>
remove unused yaffs config and usb config