mmc: msm_sdhci: Use max-frequency to get clock rate

mmc: msm_sdhci: Use max-frequency to get clock rate

msm_sdc_clk_init() uses clock-frequency to get the clock rate for SDC
clocks. However, the DT files seem to use max-frequency for the same.
Since msm_sdc_clk_init() doesn't find clock-frequency in the DT, it sets
201500000 as the clock rate and this results in timeout errors on IPQ
platforms.

Additionally, clock-frequency is not DT bindings compliant. Hence, get
clock rate using DT bindings compliant max-frequency.

Signed-off-by: Varadarajan Narayanan <varadarajan.narayanan@oss.qualcomm.com>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>