wl12xx: support p2p interfaces

Declare support for p2p interfaces, and create p2p_cli/p2p_go
roles when being asked for.

Indicate we are using a p2p interface by setting the wl->p2p flag.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>