mmc: tegra: Add SDR50 tuning support

mmc: tegra: Add SDR50 tuning support

Added tuning tap hole equations to support SDR50 mode
for SD and SDIO device.

Bug 1447641

Change-Id: I09425098c0991553df87231ea9fdccf5bae683d3
Reviewed-on: http://git-master/r/361310
(cherry picked from commit 622918573fa3e3914ed9e633d467a0433a4a8ff2)

Signed-off-by: R Raj Kumar <rrajk@nvidia.com>
Change-Id: I3a0d1178b3c085057a16a981294085b667a5e3dc
Reviewed-on: http://git-master/r/365738
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Naveen Kumar Arepalli <naveenk@nvidia.com>
Reviewed-by: Pavan Kunapuli <pkunapuli@nvidia.com>
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>