[ARM] tegra: stingray: Add ehci3 for all devices

[ARM] tegra: stingray: Add ehci3 for all devices

Even though the wifi-only model has nothing attached to ehci3, the
driver still needs to be probed.  This is because the USB register
settings are lost in LP0. So currently after the device resumes from
LP0 the first time, the current drain is 12mA higher!  When the
ehci3 driver is present, its resume code runs and restores the
registers to a known good state, which solves the power management
issue.

Change-Id: I6329704f7a1161eb139b62002a50085eb05d2fdc
Signed-off-by: Greg Meiste <w30289@motorola.com>