sh: r7780rp: irq-r7780rp needs linux/io.h.

Trivial build fix.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/boards/renesas/r7780rp/irq-r7780rp.c

@@ -9,6 +9,7 @@
  * for more details.
  */
 #include <linux/init.h>
+#include <linux/io.h>
 #include <asm/r7780rp.h>
 
 unsigned char * __init highlander_init_irq_r7780rp(void)