HHI_SYS_CPU_CLK_POSTMUX0
div = (reg & HHI_SYS_CPU_CLK_POSTMUX0) ?
HSET4(sc, offset, HHI_SYS_CPU_CLK_POSTMUX0);
HCLR4(sc, offset, HHI_SYS_CPU_CLK_POSTMUX0);