mmc: tegra: Use first valid full win for negative margins

mmc: tegra: Use first valid full win for negative margins

For negative margin calculations, use the first valid full window
in the first valid UI if Avg UI is found.
If Avg UI is not found, use first and second full windows to determine
the negative margin.
During negative margin calculation, marking each step as boundary.

Bug 1423429

Change-Id: I85cc57b1038bbce314d5bd89ef8aace117bdd8fe
Signed-off-by: Pavan Kunapuli <pkunapuli@nvidia.com>
(cherry picked from commit f3173ecf17d34644e482846d756e73fc67d9e7fa)
Reviewed-on: http://git-master/r/410195
GVS: Gerrit_Virtual_Submit
Reviewed-by: Shreshtha Sahu <ssahu@nvidia.com>
Tested-by: Shreshtha Sahu <ssahu@nvidia.com>
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>