xhci: add helpers for enabling and disabling interrupters

Simple helpers to set and clear the IE (interrupter enable) bit
for an interrupter.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230202150505.618915-5-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>