tilegx: support KGDB

Enter kernel debugger at boot with:
  --hvd UART_1=1 --hvx kgdbwait --hvx kgdboc=ttyS1,115200
or at runtime with:
  echo ttyS1,115200 > /sys/module/kgdboc/parameters/kgdboc
  echo g > /proc/sysrq-trigger

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/kernel/traps.c

@@ -240,6 +240,11 @@ static int do_bpt(struct pt_regs *regs)
 		notify_die(DIE_BREAK, "debug", regs, bundle,
 			INT_ILL, SIGTRAP);
 		break;
+	/* compiled_bpt */
+	case DIE_COMPILED_BPT:
+		notify_die(DIE_COMPILED_BPT, "debug", regs, bundle,
+			INT_ILL, SIGTRAP);
+		break;
 	/* breakpoint2_insn */
 	case DIE_SSTEPBP:
 		notify_die(DIE_SSTEPBP, "single_step", regs, bundle,