arm: tegra: tn8: lgd 7" use Tx only video clk mode

arm: tegra: tn8: lgd 7" use Tx only video clk mode

Set video clk mode to Tx only and tweak the timing
to make Tx only work in dsi_lgd_wxga_7_0 modes.
Also add the D-Phy timing.

Bug 1401244
Bug 1234973

Change-Id: Idbd18224e79d572408e74c4b5f86b1b8eac7f17f
Signed-off-by: Robert Shih <rshih@nvidia.com>
Reviewed-on: http://git-master/r/329502
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Animesh Kishore <ankishore@nvidia.com>
Reviewed-by: Kerwin Wan <kerwinw@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sachin Nikam <snikam@nvidia.com>