P2P: Do not allow peer update to clear config_methods

P2P: Do not allow peer update to clear config_methods

It could be possible for the scan results to include two entries for a
peer, one from the Listen state and the second one from the GO role. The
latter could be based on a Beason frame. If that happens and the entry
from GO is processed last, the P2P peer config_methods value could
potentially get cleared since Beacon frames do not include this
information in either WPS or P2P element. Avoid this by allowing the
config_methods value for P2P peers to be updated only if the new value
is non-zero.

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