fix(brcm): fix misspelled header inclusion guard

The header inclusion guard for some header for the Broadcom Stingray
board was misspelled.

Make the preprocessor symbol for the #ifndef and #define lines the
same, so that the double inclusion protection works as expected.

Change-Id: I19d73c854cd0689a248ce914ef35ae87c39ebf39
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/brcm/board/stingray/include/scp_cmd.h b/plat/brcm/board/stingray/include/scp_cmd.h
index 806ef56..a7ab0e5 100644
--- a/plat/brcm/board/stingray/include/scp_cmd.h
+++ b/plat/brcm/board/stingray/include/scp_cmd.h
@@ -5,7 +5,7 @@
  */
 
 #ifndef SCP_CMD_H
-#define SCP_SMD_H
+#define SCP_CMD_H
 
 #include <stdint.h>