xhci: convert TRB_CYCLE to le32 before using it to set Link TRB's cycle bit

This patch converts TRB_CYCLE to le32 to update correctly the Cycle Bit in
'control' field of the link TRB.
This bug was found using sparse.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>