Blackfin: add support for the DBG (debug output) pseudo insn

Another pseudo insn used by Blackfin simulators.  Also factor some now
common register lookup code out of the DBGA handlers.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index 9369836..59c1df7 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -213,6 +213,8 @@
 		if (!kernel_mode_regs(fp) && get_instruction(&opcode, (unsigned short *)fp->pc)) {
 			if (execute_pseudodbg_assert(fp, opcode))
 				goto traps_done;
+			if (execute_pseudodbg(fp, opcode))
+				goto traps_done;
 		}
 #endif
 		info.si_code = ILL_ILLOPC;