P2P: Fix crash when failed to create GO interface

P2P: Fix crash when failed to create GO interface

wpa_supplicant crashes if driver configuration for AP mode interface
configuration fails after group negotiation. This is because of a
regression from commit 1075b2957169d8f9d6dddd7679339c751dc9515b that
ends up freeing the wpa_s instance from within
wpa_supplicant_create_ap() without the caller knowing.

Fix this by using an eloop timeout to free remove the P2P group so that
wpa_supplicant_create_ap() and especially wpa_supplicant_associate()
callers do not need to know about interface getting possibly removed. In
addition, move the P2P specific code into p2p_supplicant.c where it
really belongs. This allows the already existing group formation timeout
to be used by reducing the timeout to zero.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>