cfg: add missing Stellaris Blizzard info

Change-Id: I1d6fb9a2ec8d87267a266f68c01ce032450e45d5
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/392
Tested-by: jenkins

tcl/target/stellaris.cfg

@@ -28,7 +28,8 @@ if { [info exists CHIPNAME] } {
 # CPU TAP ID 0x1ba00477 for early Sandstorm parts
 # CPU TAP ID 0x2ba00477 for later SandStorm parts, e.g. lm3s811 Rev C2
 # CPU TAP ID 0x3ba00477 for Cortex-M3 r1p2 (on Fury, DustDevil)
-# CPU TAP ID 0x4ba00477 for Cortex-M3 r2p0 (on Tempest)
+# CPU TAP ID 0x4ba00477 for Cortex-M3 r2p0 (on Tempest, Firestorm)
+# CPU TAP ID 0x4ba00477 for Cortex-M4 r0p1 (on Blizzard)
 # ... we'll ignore the JTAG version field, rather than list every
 # chip revision that turns up.
 if { [info exists CPUTAPID] } {