Wifi: Write sysfs fs_ready 1 in init rc

When boot complete, write fs_ready 1 to notify cnss2.
Note fs_ready must not be written too early, otherwise
it will not download firmware successfully.

Bug: 202809487
Test: Build pass
Change-Id: I990257d168550e512ae94287ca79095201b16e2b

conf/init.lynx.rc

@@ -37,3 +37,7 @@ on property:vendor.mfgapi.touchpanel.permission=1
 on post-fs-data
     chown system system /dev/goodix_fp
     exec_background - system shell -- /vendor/bin/trusty_apploader /vendor/firmware/g7.app
+
+# Wifi
+on property:sys.boot_completed=1
+    write /sys/bus/platform/drivers/cnss2/qcom,cnss-qca6490/fs_ready 1