When starting a p2p mgmt interface, enable its device role. This
allows us to keep the sta role disabled and scan on the dev role.

In general, p2p management interfaces cannot send vif-specific commands
to FW, as the vif role id is invalid. Only off-channel data and scans
happen on this vif, so most ops are not relevant.

If the vif is a p2p mgmt vif, block some mac80211 ops.

Configure rate policies for p2p mgmt interface, as
otherwise p2p packets come out with arbitrary rates.

Since wpa_supplicant currently doesn't support standalone
p2p device mode (without another attached managed interface),
add p2p device to the allowed interface combinations without
decreasing the allowed station count.

Moreover, increase the station count in some cases, as AP
mode usually starts as station interface, and the AP interface
is now different from the p2p management one).

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>