AT91: change includes from asm/arch/io.h to asm/io.h

and remove the now unused asm/arch-at91/io.h

Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>
diff --git a/drivers/rtc/at91sam9_rtt.c b/drivers/rtc/at91sam9_rtt.c
index ed44016..ff4acb5 100644
--- a/drivers/rtc/at91sam9_rtt.c
+++ b/drivers/rtc/at91sam9_rtt.c
@@ -38,9 +38,9 @@
 #include <common.h>
 #include <command.h>
 #include <rtc.h>
+#include <asm/io.h>
 #include <asm/errno.h>
 #include <asm/arch/hardware.h>
-#include <asm/arch/io.h>
 #include <asm/arch/at91_rtt.h>
 #include <asm/arch/at91_gpbr.h>