clk: mmp2: fix the clock id for sdh2_clk and sdh3_clk

A typo that makes it impossible to get the correct clocks for
MMP2_CLK_SDH2 and MMP2_CLK_SDH3.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Fixes: 1ec770d9

 ("clk: mmp: add mmp2 DT support for clock driver")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>