cfg: correct Stellaris LM3S811 config typo

This only effects the older Stellaris LM3S811 kits (rev B and below).

Change-Id: Ie068cce7748fede9e7113ea63a69c96222c809fa
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/401
Tested-by: jenkins

tcl/interface/luminary-lm3s811.cfg

@@ -12,7 +12,7 @@
 #
 
 interface ft2232
-ft2232_device_desc "Stellaris Evaluation Board"
+ft2232_device_desc "LM3S811 Evaluation Board"
 ft2232_layout evb_lm3s811
 ft2232_vid_pid 0x0403 0xbcd9