sunxi: Set default CPU clock rate to 1008 MHz for sun9i (A80)

In Allwinner's SDK the A80 is clocked to 1008 MHz by default.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>