conf/machine: add support for rk312x
conf/machine: add support for rk312x

RK312X are a serial called RK audio. All of them sharing
the simliar hardware configure. A quad-core ARM Cortex-A7
processor with separately Neon and FPU coprocessor, they
also share a 256KB L2 Cache.

All chips in this serial have a Mali 400 MP2 GPU.

Signed-off-by: Randy 'ayaka' Li <d9da4b1326b089e1905c19b389e4c8b735aa18ad@soulik.info>

hizukiayaka/meta-rockchip,hizukiayaka/meta-rockchip,hizukiayaka/meta-rockchip