ARM: dts: sun5i: add A10s/A13 mali gpu support fallback

The A10s/A13 mali gpu was not defined in device tree
Add A10 mali gpu as a fallback for A10s/A13
Tested with Olimex-A13-SOM / Olimex-A13-OlinuXino-MICRO
"kmscube" 3d cube on screen (60fps / 10%cpu)
Versions: Lima:1.1.0 EGL:1.4 OpenGLES:2.0 Mesa:20.2.2

Signed-off-by: Sergio Sota <sergiosota@fanamoel.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210108103819.322901-1-sergiosota@fanamoel.com