mmc: sdhci-of-arasan: Use Mask writes for Tap delays

Mask the ITAP and OTAP delay bits before updating with the new
tap value for Versal platform.

Fixes: 1a470721 ("sdhci: arasan: Add support for Versal Tap Delays")
Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Signed-off-by: Manish Narani <manish.narani@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1605515565-117562-3-git-send-email-manish.narani@xilinx.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>