sh: kgdb: Fix up basic SMP support.

kgdb needs a kgdb_roundup_cpus() definition in the architecture backend,
so just copy over the MIPS version, which already does what we want.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/kgdb.c

@@ -264,6 +264,18 @@ BUILD_TRAP_HANDLER(singlestep)
 	local_irq_restore(flags);
 }
 
+static void kgdb_call_nmi_hook(void *ignored)
+{
+	kgdb_nmicallback(raw_smp_processor_id(), NULL);
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+	local_irq_enable();
+	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
+	local_irq_disable();
+}
+
 static int __kgdb_notify(struct die_args *args, unsigned long cmd)
 {
 	int ret;