read p2p config file name

In KK, since we are using single interface, WiFi
configuration data is being over written by P2P
configuration data in wpa_supplicant.conf file which
is invalid. Upon reboot it will not connect to Wifi
since WiFi configuration data is being overwritten
after P2P connection.So read p2p configuration file
name from supplicant command line argument which will
not overwrite the wpa_supplicant.conf file.

bug 1485880
bug 200005079

Change-Id: I7d1c53d426939924f9d508fb280517d0bd91ae98
Reviewed-on: http://git-master/r/344381
(cherry picked from commit 49ac317f8e35e609a4431263f47936a942394df0)
Reviewed-on: http://git-master/r/389688
Reviewed-by: Narayan Reddy <narayanr@nvidia.com>
Tested-by: Narayan Reddy <narayanr@nvidia.com>
Reviewed-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Reviewed-by: Harshada Kale <hkale@nvidia.com>