Label /data/misc/wifi/hostapd with wpa_socket type.

hostapd creates sockets under /data/misc/wifi/hostapd.
Ensure that they are labeled correctly both at runtime
(type_transition) and during the init.rc restorecon_recursive /data
(file_contexts).

Addresses denials such as:
 avc:  denied  { create } for  pid=20476 comm="hostapd" name="wlan0" scontext=u:r:hostapd:s0 tcontext=u:object_r:wifi_data_file:s0 tclass=sock_file
 avc:  denied  { setattr } for  pid=20476 comm="hostapd" name="wlan0" dev="mmcblk0p23" ino=619005 scontext=u:r:hostapd:s0 tcontext=u:object_r:wifi_data_file:s0 tclass=sock_file
 avc:  denied  { unlink } for  pid=20476 comm="hostapd" name="wlan0" dev="mmcblk0p23" ino=619005 scontext=u:r:hostapd:s0 tcontext=u:object_r:wifi_data_file:s0 tclass=sock_file

Change-Id: I80a443faeb6017a9d6cbdb8da9d7416f29a7b85f
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>