mmc: sdhci: Add support for dt caps & caps mask

The sdhci capabilities registers can be incorrect. The
sdhci-caps-mask and sdhci-caps dt properties specify which bits of
the registers are incorrect and what their values should be. This
patch makes the sdhci driver use those properties to correct the caps.
Also use "dev_read_u64_default" instead of "dev_read_u32_array" for
caps mask.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>