sh: smp: Provide a generic IPI handler.

This provides a generic smp_message_recv() routine (based on the PPC
one), that IPI IRQs can wrap in to.

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

arch/sh/include/asm/smp.h

@@ -26,6 +26,7 @@ extern int __cpu_logical_map[NR_CPUS];
 #define SMP_MSG_FUNCTION_SINGLE	2
 #define SMP_MSG_NR		3
 
+void smp_message_recv(unsigned int msg);
 void plat_smp_setup(void);
 void plat_prepare_cpus(unsigned int max_cpus);
 int plat_smp_processor_id(void);