xhci: Fix some regressions introduced in 3.14.

Hi Greg,

Here's four patches for 3.14.

One of them adds an xHCI host quirk, and the other three of them fix
regressions introduced in 3.14.  One regression causes USB 3.0 Link PM to
be enabled on all xHCI hosts (even those that may not support it), which
causes some USB 3.0 devices to not enumerate.  A second regression causes
some xHCI hosts that don't support 64-bit addressing to stop responding to
commands and die.

Note, these patches don't fix the recent usbfs regression that was caused
by commit 35773dac5f862cb1c82ea151eba3e2f6de51ec3e "usb: xhci: Link TRB
must not occur within a USB payload burst".  I'm waiting for those patches
to be tested.

Please pull usb-linus into usb-next, as I have feature patches that rely on
140e3026a57a Revert "usbcore: set lpm_capable field for LPM capable root

Sarah Sharp
Revert "xhci: replace xhci_read_64() with readq()"

This reverts commit e8b373326d8efcaf9ec1da8b618556c89bd5ffc4.  Many xHCI
host controllers can only handle 32-bit addresses, and writing 64-bits
at a time causes them to fail.  Reading 64-bits at a time may also cause
them to return 0xffffffff, so revert this commit as well.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
5 files changed