brcmfmac: support creation of P2P_DEVICE through user-space

brcmfmac: support creation of P2P_DEVICE through user-space

The current driver code creates a P2P_DEVICE through a module
parameter. This device has a dummy netdevice which is not how this
interface type is intended. This patch add proper support for the
P2P_DEVICE interface type. This requires a wpa_supplicant with such
support as well.

Reviewed-by: Pieter-Paul Giesberts <[email protected]>
Reviewed-by: Piotr Haber <[email protected]>
Reviewed-by: Hante Meuleman <[email protected]>
Signed-off-by: Arend van Spriel <[email protected]>
Signed-off-by: John W. Linville <[email protected]>