Revert "p2p: Add p2p_no_group_iface flag to p2p conf file"

 * Most devices hate this. To support it, a device needs NVRAM
   setup for it.

This reverts commit 6b7661db4e2e3c0a37e3935f906ef9013ddef824.

Change-Id: I1e91c9116c22483049e95c25f6166d2472164d18