imx: fix header inclusion guards

It seems like the header inclusion guards for some IMX related headers
were misspelled or got out of sync.

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

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/include/asm/arch-imx9/sys_proto.h b/arch/arm/include/asm/arch-imx9/sys_proto.h
index ba97f92..2f7a129 100644
--- a/arch/arm/include/asm/arch-imx9/sys_proto.h
+++ b/arch/arm/include/asm/arch-imx9/sys_proto.h
@@ -4,7 +4,7 @@
  */
 
 #ifndef __ARCH_IMX9_SYS_PROTO_H
-#define __ARCH_NMX9_SYS_PROTO_H
+#define __ARCH_IMX9_SYS_PROTO_H
 
 #include <asm/mach-imx/sys_proto.h>