clk: mmp: pxa168: add muxes for more peripherals

clk: mmp: pxa168: add muxes for more peripherals

The TWSI, KPC, PWM, and DFC peripherals didn't have their muxes modeled
in the code, but the PXA168 datasheet shows that they are indeed muxed:

- TWSI can be 31.2 MHz or 62.4 MHz
- KPC can be 32 kHz, 16 kHz, or 26 MHz
- PWM can be 13 MHz or 32 kHz
- DFC can be 156 MHz or 78 MHz

Signed-off-by: Doug Brown <doug@schmorgal.com>
Link: https://lore.kernel.org/r/20220612192937.162952-8-doug@schmorgal.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>