cnd: add policy to allow cne to use wpa supplicant

This is to resolve the following denials seen when connecting to supplicant:
avc: denied { search } for name="wpa" dev="mmcblk0p75" ino=524339 scontext=u:r:cnd:s0 tcontext=u:object_r:wpa_data_file:s0 tclass=dir permissive=1
avc: denied { write } for name="sockets" dev="mmcblk0p75" ino=524340 scontext=u:r:cnd:s0 tcontext=u:object_r:wpa_data_file:s0 tclass=dir permissive=1
avc: denied { add_name } for name="wpa_ctrl_816-1" scontext=u:r:cnd:s0 tcontext=u:object_r:wpa_data_file:s0 tclass=dir permissive=1
avc: denied { create } for name="wpa_ctrl_816-1" scontext=u:r:cnd:s0 tcontext=u:object_r:wpa_data_file:s0 tclass=sock_file permissive=1
avc: denied { setattr } for name="wpa_ctrl_816-1" dev="mmcblk0p75" ino=525291 scontext=u:r:cnd:s0 tcontext=u:object_r:wpa_data_file:s0 tclass=sock_file permissive=1

Change-Id: Ie82b47383097bda85e75b3e1ffe7381264a682e3