AM/DM37x: add ES1.2 silicon type into account

The missing value for ES1.2 silicon revision is mentioned in
sprugn4m.pdf, and the recent TI Beagleboard XM is powered by it,
so let support the revision.

tcl/target/amdm37x.cfg

@@ -29,7 +29,7 @@ if { [info exists CHIPTYPE] } {
    switch $CHIPTYPE {
       dm37x {
          # Primary TAP: ICEpick-C (JTAG route controller) and boundary scan
-         set _JRC_TAPID "-expected-id 0x1b89102f -expected-id 0x0b89102f"
+         set _JRC_TAPID "-expected-id 0x2b89102f -expected-id 0x1b89102f -expected-id 0x0b89102f"
       }
       am35x {
          # Primary TAP: ICEpick-C (JTAG route controller) and boundary scan