mwifiex: have same priority for AP and station traffic

Currently AP interface has higher priority over station. Hence
separate entries are created in "adapter->bss_prio_tbl" for these
interfaces and station packet is dequeued only if there is not
packet in queue for AP. It is observed that ping for station
interface doesn't work if heavy traffic is running on AP.

The problem is fixed by having same priority for both the
interfaces. This patch also removes an extra initialisation
for "priv->bss_priority".

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>