i40iw: add hw and utils files

i40iw_hw.c, i40iw_utils.c and i40iw_osdep.h are files to handle
interrupts and processing.

Changes since v1:
        Cleanup/removed some macros reported by Christoph Hellwig.

Acked-by: Anjali Singhai Jain <[email protected]>
Acked-by: Shannon Nelson <[email protected]>
Signed-off-by: Faisal Latif <[email protected]>
Signed-off-by: Doug Ledford <[email protected]>

Author: fsl-latif