init: add more wifi firmware paths

Some devices' wifi firmware is under /data/misc/wifi.
Wlan module won't be loaded successfully if we don't change this.

A binary "/system/bin/wlan_detect" copies wifi firmware from /system/etc/wifi to /data/misc/wifi and load it then.

We can't even insmod wlan.ko without this!

Change-Id: Idcbd337c090acb86aefad8c6c69537c8ba8faec6
Signed-off-by: dianlujitao <dianlujitao@gmail.com>