zenfone7: Add system_ext to fstab.qcom

Change-Id: I859f89c1f9f62cb810c387cfccfe5a93cfe29b52
diff --git a/fstab.qcom b/fstab.qcom
index 5258830..0f3b012 100755
--- a/fstab.qcom
+++ b/fstab.qcom
@@ -36,6 +36,7 @@
 
 #<src>                                                 <mnt_point>            <type>  <mnt_flags and options>                            <fs_mgr_flags>
 system                                                  /system                ext4    ro,barrier=1,discard                                 wait,slotselect,avb=vbmeta_system,logical,first_stage_mount,avb_keys=/avb/q-gsi.avbpubkey:/avb/r-gsi.avbpubkey:/avb/s-gsi.avbpubkey
+system_ext                                              /system_ext            ext4    ro,barrier=1,discard                                 wait,slotselect,avb=vbmeta_system,logical,first_stage_mount
 product                                                 /product               ext4    ro,barrier=1,discard                                 wait,slotselect,avb=vbmeta_system,logical,first_stage_mount
 vendor                                                  /vendor                ext4    ro,barrier=1,discard                                 wait,slotselect,avb,logical,first_stage_mount
 odm                                                     /odm                   ext4    ro,barrier=1,discard                                 wait,slotselect,avb,logical,first_stage_mount