sunxi-hdmi: Add 1366x768 mode

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
arm:configs:sunxi: W1_SUNXI=m
Changes from cubie/sunxi-3.4.79 branch
https://github.com/cubieboard/linux-sunxi/commit/7d4f447dec7372b7fcc728c475eb0929a0ee9052#diff-0a7b6db5ece63bb4e3abc6ff79d1f19eR181
Fix errors