mwifiex: module load parameter for interface creation

This patch adds module load parameter driver_mode for mwifiex
which would enable driver to create AP or P2P client interface while loading
module. driver_mode is bitmap of interface modes for station, AP and
P2P client.

Station interface is created by default and is unaffected by driver_mode
parameter.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>