hal_wifi: Allow HAL to reload wifi firmware

am: 85e3e7d6

Change-Id: I875f2ac6a830fec679b8f2ea4fc22a65faed4a6e

public/hal_wifi.te

@@ -20,3 +20,5 @@ allow hal_wifi self:capability { net_admin net_raw };
 allow hal_wifi self:netlink_socket create_socket_perms_no_ioctl;
 # newer kernels (e.g. 4.4 but not 4.1) have a new class for sockets
 allow hal_wifi self:netlink_generic_socket create_socket_perms_no_ioctl;
+# hal_wifi writes firmware paths to this file.
+allow hal_wifi sysfs_wlan_fwpath:file { w_file_perms };