arm: ti: Add missing guards to headers

To prevent possible double inclusions in future.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/include/environment/ti/mmc.h b/include/environment/ti/mmc.h
index b987f71..4305ebd 100644
--- a/include/environment/ti/mmc.h
+++ b/include/environment/ti/mmc.h
@@ -6,6 +6,9 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#ifndef __TI_MMC_H
+#define __TI_MMC_H
+
 #define DEFAULT_MMC_TI_ARGS \
 	"mmcdev=0\0" \
 	"mmcrootfstype=ext4 rootwait\0" \
@@ -66,3 +69,5 @@
 				"fi;" \
 			"fi;" \
 		"fi;\0"
+
+#endif /* __TI_MMC_H */