sunxi: Adjust Ippo_q8h_v1_2_a33_1024x600 dts filename to match the upstream kernel

sun8i-a33-ippo-q8h-v1.2-lcd1024x600.dts has been merged into the upstream
Linux kernel as sun8i-a33-ippo-q8h-v1.2.dts, adjust u-boot to follow.

Note we've never shipped a final u-boot version with the old name, so this
is safe todo.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>