ARM: dts: mstar: Add a dts for Miyoo Mini

Miyoo has released a portable retro games machine based
on the SigmaStar SSD202D. Add the initial device tree
for this machine. Just enough to get to an initramfs
shell.

Link: http://linux-chenxing.org/infinity2/miyoomini/


Signed-off-by: Daniel Palmer <daniel@0x0f.com>