usb: host: xhci-tegra: Reuse stored register base address

The base address of the XUSB controller's registers is already stored in
the HCD. Move assignment to the HCD fields to an earlier point so that
they can be reused in the tegra_xusb_config() function. This avoids the
need to pass the base address as an extra parameter, which in turn comes
in handy in subsequent patches that need to call this function from the
suspend/resume paths where these values are no longer readily available.

Based on work by JC Kuo <jckuo@nvidia.com>.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20191206140653.2085561-7-thierry.reding@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>