Revert "xhci: Set scatter-gather limit to avoid failed block writes."

This reverts commit f2d9b991.

We are ripping out commit 35773dac "usb:
xhci: Link TRB must not occur within a USB payload burst" because it's a
hack that caused regressions in the usb-storage and userspace USB
drivers that use usbfs and libusb.  This commit attempted to fix the
issues with that patch.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org #3.12