mwifiex: add support for P2P client in interface type change

When cfg80211 calls to change interface type for P2P client,
send P2P mode config commands to firmware.

Signed-off-by: Stone Piao <piaoyun@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>