kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin

The new debug core api requires all architectures that use to debug
core to implement a function to set the program counter.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/kernel/kgdb.c

@@ -439,6 +439,11 @@ int kgdb_validate_break_address(unsigned long addr)
 	return -EFAULT;
 }
 
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+{
+	regs->retx = ip;
+}
+
 int kgdb_arch_init(void)
 {
 	kgdb_single_step = 0;