Update readme.md

Just separated the board identifier from the revision on the Arrow BeagleBone Black Industrial. Also added a place holder for the Element14 BeagleBone Black Industrial to avoid them being "scooped".

readme.md

@@ -15,7 +15,11 @@ SeeedStudio BeagleBone Green:
 
 Arrow BeagleBone Black Industrial:
 
-    AIA0: [aa 55 33 ee 41 33 33 35  42 4e 4c 54 41 49 41 30 |.U3.A335BNLTAIA0|]
+      A0: [aa 55 33 ee 41 33 33 35  42 4e 4c 54 41 49 41 30 |.U3.A335BNLTAIA0|]
+
+Element14 BeagleBone Black Industrial:
+
+      A0: [aa 55 33 ee 41 33 33 35  42 4e 4c 54 45 49 41 30 |.U3.A335BNLTEIA0|]
 
 Scripts to support customized image generation for many arm systems