arm64: rockchip: clk: Add MUXRAW macros

Some clocks in the RK3328 SoC (and possibly others) have registers not in
the CLKSEL_CON range. Add a macros for muxes which lives not in the range
of CLKSEL_CON which just takes a raw offset.

(cherry picked from commit deff1fb3dccb13b6961b1e8595f74a2134e65b93)