xhci: Refactor port status into a new function.
xhci: Refactor port status into a new function.

The hub control function is *way* too long.  Refactor it into a new
function, and document the side effects of calling that function.

Signed-off-by: Sarah Sharp <d4c4fc5069677be84f589aa6e14eedffef9ba12f@linux.intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs