ARM: MX31: Fix file name label

Commit 5d2c154 (IMX: MX31: Cleanup include files and drop nasty #ifdef in drivers)
renamed mx31-imx-regs.h to imx-regs.h.

Change the file label accordingly.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

arch/arm/include/asm/arch-mx31/imx-regs.h

@@ -21,8 +21,8 @@
  * MA 02111-1307 USA
  */
 
-#ifndef __ASM_ARCH_MX31_REGS_H
-#define __ASM_ARCH_MX31_REGS_H
+#ifndef __ASM_ARCH_MX31_IMX_REGS_H
+#define __ASM_ARCH_MX31_IMX_REGS_H
 
 #if !(defined(__KERNEL_STRICT_NAMES) || defined(__ASSEMBLY__))
 #include <asm/types.h>
@@ -774,4 +774,4 @@ enum iomux_pins {
 #define MXC_EHCI_IPPUE_DOWN		(1 << 8)
 #define MXC_EHCI_IPPUE_UP		(1 << 9)
 
-#endif /* __ASM_ARCH_MX31_REGS_H */
+#endif /* __ASM_ARCH_MX31_IMX_REGS_H */