firmware: tegra: Add XHCI firmware v50.07 for T210

Add firmware file for the T210 XHCI controller.  Note that this is only
compatible with T210 (T124 should continue using nvidia/tegra124/xusb.bin).
Signed-off-by: Andrew Chew <achew@nvidia.com>
Signed-off-by: Kyle McMartin <kyle@kernel.org>

WHENCE

@@ -2725,8 +2725,9 @@ Licence: Redistributable. See LICENCE.siano for details
 
 --------------------------------------------------------------------------
 
-Driver: xhci-tegra -- NVIDIA Tegra124 XHCI driver
+Driver: xhci-tegra -- NVIDIA Tegra XHCI driver
 
 File: nvidia/tegra124/xusb.bin
+File: nvidia/tegra210/xusb.bin
 
 Licence: Redistributable. See LICENCE.nvidia for details