pcie: host: tegra: reduce root port L1.2 threshold

pcie: host: tegra: reduce root port L1.2 threshold

reduces root port's ASPM L1.2 threshold value from
106 us to 55 us to let link go into L1.2 when BCM4356
WiFi chip is end point and is connected to access point

Bug 200082310

Reviewed-on: http://git-master/r/754925
(cherry picked from commit 67cb3c9ebd780fddbb64b7da32970dfbe13f11fb)
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Change-Id: Ib1f763244cc025fff80f0c411be802736b1a84b1
Reviewed-on: http://git-master/r/755973
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>