mmc: sdhci: fix chip detect gpio property name

The standard property name for chip-detect gpio is "cd-gpios". All
in-tree DT files use only this name.

Fixes: 451931ea ("mmc: sdhci: Read cd-gpio from devicetree")
Cc: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Peng Fan <peng.fan@nxp.com>