arm: tegra: fb: Update fix line_length

Update framebuffer's fix line_length parameter when changing
video mode dynamically.The new line_length should be according
to new x resolution. On addition, check the return value from
dc driver while setting a mode.

Bug 1163682
Bug 1056767
Bug 1056782
Signed-off-by: Shashank Sharma <shashanks@nvidia.com>
Change-Id: Ib0ab48474f0af3235556a7f7f0d8354af3b50994
Reviewed-on: http://git-master/r/147511
(cherry picked from commit 5856c4afde9459ba6afaf2cdcb07361d9fbf8c79)
Reviewed-on: http://git-master/r/160788
Tested-by: Matthew Pedro <mapedro@nvidia.com>
Reviewed-by: Winnie Hsu <whsu@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User