Microchip: XEC GPIO driver interrupt enable fix part 2

Fixes issue 34879
This PR updates previous PR's 37138 and 37139.
Refer to issue 34879 for information from MCHP HW
designers. A delay after enabling interrupts is a
more appropriate work-around than depending upon
behavior of ARM DMB instruction.

Signed-off-by: Scott Worley <scott.worley@microchip.com>