device/mmio.h: Add include file for MMIO ops

MMIO operations are arch-agnostic so the include
path should not be arch/.

Change-Id: I0fd70f5aeca02e98e96b980c3aca0819f5c44b98
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/31691
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/sifive/fu540/bootblock.c

@@ -13,7 +13,7 @@
  * GNU General Public License for more details.
  */
 
-#include <arch/io.h>
+#include <device/mmio.h>
 #include <bootblock_common.h>
 #include <console/console.h>
 #include <soc/addressmap.h>

src/soc/sifive/fu540/clint.c

@@ -15,7 +15,7 @@
 
 #include <mcall.h>
 #include <stdint.h>
-#include <arch/io.h>
+#include <device/mmio.h>
 #include <soc/addressmap.h>
 
 void mtime_init(void)

src/soc/sifive/fu540/clock.c

@@ -13,7 +13,7 @@
  * GNU General Public License for more details.
  */
 
-#include <arch/io.h>
+#include <device/mmio.h>
 #include <console/console.h>
 #include <soc/clock.h>
 #include <soc/addressmap.h>

src/soc/sifive/fu540/otp.c

@@ -16,7 +16,7 @@
 #include <stddef.h>
 #include <delay.h>
 #include <arch/barrier.h>
-#include <arch/io.h>
+#include <device/mmio.h>
 #include <console/console.h>
 #include <console/uart.h>
 #include <soc/addressmap.h>