wifi: remove p2p interface on supplicant stop

remove p2p interface on wpa_supplicant stop
so next time it is started it won't fail when trying
to create p2p again

Change-Id: I7a4c5e9a82a013afc75548d175d5850d67fcd927
Merge branch 'cm-11.0' of git://github.com/CyanogenMod/android_hardware_libhardware_legacy into cm-11.0