mmc: sdhci-of-dwcmshc: add ACPI support for BlueField-3 SoC

mmc: sdhci-of-dwcmshc: add ACPI support for BlueField-3 SoC

This commit adds ACPI support in the sdhci-of-dwcmshc driver for
BlueField-3 SoC. It has changes to only use the clock hierarchy
for Deviec Tree since the clk is not supported by ACPI. Instead,
ACPI can define 'clock-frequency' which is parsed by existing
sdhci_get_property(). This clock value will be returned in function
dwcmshc_get_max_clock().

Signed-off-by: Liming Sun <limings@nvidia.com>
Reviewed-by: Khalil Blaiech <kblaiech@nvidia.com>
Link: https://lore.kernel.org/r/1616453211-275165-1-git-send-email-limings@nvidia.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>