sepolicy : Added wifihal sock perms and allow clients to connect

Added wifihal directory in /dev/sockets path.
Wifi hal allows its authenticated clients to send nl msgs to it.
Lowi module is one of its clients and hence added socket permissions
to access wifihal control interface.

CRs-Fixed: 2424252
Change-Id: I9aa7b54f2f944d59148508eace3c658a23e5d2d8