mwifiex: set txpd when send a mgmt frame for AP and GO mode

Set packet type and packet offset in txpd when send a mgmt frame
in AP and GO mode.

Signed-off-by: Stone Piao <piaoyun@marvell.com>
Signed-off-by: Kevin Gan <ganhy@marvell.com>
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>