clk: mmp: pxa168: add clocks for SDH2 and SDH3

The PXA168 has four SDHC peripherals. This commit adds the last two.

Signed-off-by: Doug Brown <doug@schmorgal.com>
Link: https://lore.kernel.org/r/20220612192937.162952-11-doug@schmorgal.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>