xhci: tegra: load fw from filesystem earlier

xhci: tegra: load fw from filesystem earlier

Loading firmware from filesystem takes much time. Enabing vbus regualtor
before loading firmware will cause the time gap between vbus ON and host
controller ready too large. So, we move the time of firmware loading
earlier.

Bug 200067006

Change-Id: I63ecbd9e65f3bb56db564f72cc417fc4f76adbc3
Signed-off-by: Henry Lin <henryl@nvidia.com>
Reviewed-on: http://git-master/r/736193
Reviewed-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-by: ChihMin Cheng <ccheng@nvidia.com>
Reviewed-by: Ashutosh Jha <ajha@nvidia.com>