[PATCH v2 0/6] support hi3xxx soc

[Haojian Zhuang]

Changelog:
v2:
1. Reuse mux & divider driver. So append CLK_MUX_HIWORD_MASK &
CLK_DIVIDER_HIWORD_MASK for Hi3620 SoC.
2. Fix system timer running too fast because wrong divider is choosen.
3. Remove .init_irq in DT machine descriptor.