mmc: sdhci-of-arasan: Issue DLL reset explicitly

In the current implementation DLL reset will be issued for
each ITAP and OTAP setting inside ATF, this is creating issues
in some scenarios and this sequence is not inline with the TRM.
To fix the issue, DLL reset should be removed from the ATF and
host driver will request it explicitly.
This patch update host driver to explicitly request for DLL reset
before ITAP (assert DLL) and after OTAP (release DLL) settings.

Fixes: a5c8b2ae

 ("mmc: sdhci-of-arasan: Add support for ZynqMP Platform Tap Delays Setup")
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/1605515565-117562-4-git-send-email-manish.narani@xilinx.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>