arm: tegra: power: add pcie dependency to xusb ops

arm: tegra: power: add pcie dependency to xusb ops

Due to a HW bug 1320346 in t12x/t13x, PCIE needs to be unpowergated when XUSB
is to be accessed.  Currently PCIE powergating ops need to be invoked from XUSB
driver since powergating module doesn't internally handle this dependency.

This patch implements this dependency within the powergating module so that
xhci-tegra driver can stay chip-agnostic.

Bug 1451279
Bug 1524744

Change-Id: Id750461f234749df484aa1c1daad7bbc7177d5d4
Signed-off-by: Haribabu Narayanan <hnarayanan@nvidia.com>
Reviewed-on: http://git-master/r/424035
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Reviewed-by: Sumeet Gupta <sumeetg@nvidia.com>
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>