86xx: Add support for 'cpu disable' command

Support disabling of a core via user command 'cpu disable'.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/cpu/mpc86xx/mp.c b/cpu/mpc86xx/mp.c
index ecdf2fb..b4a0faa 100644
--- a/cpu/mpc86xx/mp.c
+++ b/cpu/mpc86xx/mp.c
@@ -48,8 +48,22 @@
 
 int cpu_disable(int nr)
 {
-	/* dummy function so common/cmd_mp.c will build */
-	return 1;
+	volatile immap_t *immap = (immap_t *) CONFIG_SYS_CCSRBAR;
+	volatile ccsr_gur_t *gur = &immap->im_gur;
+
+	switch (nr) {
+	case 0:
+		setbits_be32(&gur->devdisr, MPC86xx_DEVDISR_CPU0);
+		break;
+	case 1:
+		setbits_be32(&gur->devdisr, MPC86xx_DEVDISR_CPU1);
+		break;
+	default:
+		printf("Invalid cpu number for disable %d\n", nr);
+		return 1;
+	}
+
+	return 0;
 }
 
 int cpu_release(int nr, int argc, char *argv[])