dt-bindings: mmc: arasan: Add compatible strings for Intel Keem Bay

Add new compatible strings in sdhci-of-arasan.c to support Intel Keem Bay
eMMC/SD/SDIO controller, based on Arasan SDHCI 5.1.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Link: https://lore.kernel.org/r/20200526062758.17642-2-wan.ahmad.zainie.wan.mohamad@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>