ARM: OMAP4+: Allow kexec on SMP variants

Kexec needs omap4_cpu_kill, otherwise kexec will produce on SMP:

kexec_load failed: Invalid argument

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap-hotplug.c

@@ -64,3 +64,9 @@ void omap4_cpu_die(unsigned int cpu)
 		pr_debug("CPU%u: spurious wakeup call\n", cpu);
 	}
 }
+
+/* Needed by kexec and platform_can_cpu_hotplug() */
+int omap4_cpu_kill(unsigned int cpu)
+{
+	return 1;
+}