MIPS: OCTEON: Add SMP support for OCTEON cn78xx et al.

OCTEON chips with the CIU3 interrupt controller use a different IPI
mechanism that previous models.

Add plat_smp_ops for the cn78xx and probing code to choose between the
two types of ops.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12499/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/cavium-octeon/setup.c

@@ -43,8 +43,6 @@
 #include <asm/octeon/cvmx-mio-defs.h>
 #include <asm/octeon/cvmx-rst-defs.h>
 
-extern struct plat_smp_ops octeon_smp_ops;
-
 #ifdef CONFIG_PCI
 extern void pci_console_init(const char *arg);
 #endif
@@ -888,7 +886,7 @@ void __init prom_init(void)
 #endif
 
 	octeon_user_io_init();
-	register_smp_ops(&octeon_smp_ops);
+	octeon_setup_smp();
 }
 
 /* Exclude a single page from the regions obtained in plat_mem_setup. */