clk: tegra: Initialize xusb clocks

Initialize the XUSB-related clocks with appropriate parents and rates
for both Tegra114 and Tegra124.

Signed-off-by: Jim Lin <jilin@nvidia.com>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>