app: aboot: update kernel cmd line for display params

Don't clutter the kernel command line if the display
is not enabled.

Change-Id: Id89d61a973a4ed8ea0293b2e9c54137379c11cc1
diff --git a/app/aboot/aboot.c b/app/aboot/aboot.c
index 2738c68..01ca589 100755
--- a/app/aboot/aboot.c
+++ b/app/aboot/aboot.c
@@ -455,6 +455,7 @@
 			break;
 	}
 
+#if ENABLE_DISPLAY
 	if (cmdline) {
 		if ((strstr(cmdline, DISPLAY_DEFAULT_PREFIX) == NULL) &&
 			target_display_panel_node(display_panel_buf,
@@ -463,6 +464,7 @@
 			cmdline_len += strlen(display_panel_buf);
 		}
 	}
+#endif
 
 	if (target_warm_boot()) {
 		warm_boot = true;