Repair build fail in case CONFIG_PPC=n and CONFIG_FIT=y

Signed-off-by: Remy Bohmer <linux@bohmer.net>
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 8f83598..32fd9bb 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -524,7 +524,7 @@
 		}
 			break;
 #endif
-#ifdef CONFIG_OF_LIBFDT
+#if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_SYS_BOOTMAPSZ)
 		case BOOTM_STATE_FDT:
 		{
 			ulong bootmap_base = getenv_bootm_low();