usb: Send Set SEL before enabling parent U1/U2 timeout.

The Set SEL control transfer tells a device the exit latencies
associated with a device-initated U1 or U2 exit.  Since a parent hub may
initiate a transition to U1 soon after a downstream port's U1 timeout is
set, we need to make sure the device receives the Set SEL transfer
before the parent hub timeout is set.

This patch should be backported to kernels as old as 3.5, that contain
the commit 1ea7e0e8 "USB: Add support to
enable/disable USB3 link states."

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org