sh: sh7757: Add missing #include <asm/mmzone.h>

arch/sh/kernel/cpu/sh4a/setup-sh7757.c:1240:13: warning: no previous prototype for ‘plat_mem_setup’ [-Wmissing-prototypes]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/c9c26472151d16a2ca91f14bccd64af07a6abdd8.1709579038.git.geert+renesas@glider.beSigned-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

arch/sh/kernel/cpu/sh4a/setup-sh7757.c

@@ -17,8 +17,11 @@
 #include <linux/sh_dma.h>
 #include <linux/sh_intc.h>
 #include <linux/usb/ohci_pdriver.h>
+
 #include <cpu/dma-register.h>
 #include <cpu/sh7757.h>
+
+#include <asm/mmzone.h>
 #include <asm/platform_early.h>
 
 static struct plat_sci_port scif2_platform_data = {