mmc: tegra: Modify UI calculations in tuning

mmc: tegra: Modify UI calculations in tuning

Discrediting all the UI's from either end that are less than 30%
of the estimated UI.
Not using a discredited UI for any comparisons. If one of the UIs
in a comparison is already discredited, discrediting the other UI
as well.
Checking for multiple holes in the same window.
For margin calculations for window ends identified as tap holes, use
n'th Vmin hole for n'th Vmax hole position.

Bug 1423429

Reviewed-on: http://git-master/r/378626
(cherry picked from commit 5be59d90d446171c1ba4e4b6e776f7e92f79008f)

Change-Id: Ic71a8a18b0c41a7c88715b18e1caa04e0d992bef
Signed-off-by: Pavan Kunapuli <pkunapuli@nvidia.com>
Reviewed-on: http://git-master/r/380624
Reviewed-by: Mitch Luban <mluban@nvidia.com>
Tested-by: Mitch Luban <mluban@nvidia.com>