Revert "bcmdhd: Enable Ad-Hoc (IBSS) mode"

This reverts commit aff821c6d23594d9af1847e6a99b0922864e229d.
Revert "bcmdhd: Hardcode p2p_supported=1"

This reverts commit fb37ed420387f8680bcbcb4560e7e85f98b6026d.