ARM: dt: tegra trimslice: enable USB2 port

This was accidentally disabled by commit 2a5fdc9a "ARM: dt: tegra:
invert status=disable vs status=okay".

Cc: <stable@vger.kernel.org> # v3.5 (file is named tegra-trimslice.dts there)
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>