mmc: tegra: Set clk parent explicitly

mmc: tegra: Set clk parent explicitly

Set clk parent for sdhci device to avoid
wrong clk parent settings issues on T18x
platforms.

Bug 200218065

Change-Id: Ia4d73febc36fda92d7ea21f2bb935027574b18df
Signed-off-by: Anubhav Jain <anubhavj@nvidia.com>
Signed-off-by: R Raj Kumar <rrajk@nvidia.com>
Reviewed-on: http://git-master/r/1181184
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User