malta: enable RTC support

This is actually required in order for a Linux kernel to boot
successfully on a physical Malta board. Without enabling the RTC, a
Malta Linux kernel will get stuck in its estimate_frequencies function
on boot.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
diff --git a/drivers/rtc/mc146818.c b/drivers/rtc/mc146818.c
index 5f9d359..f7cf106 100644
--- a/drivers/rtc/mc146818.c
+++ b/drivers/rtc/mc146818.c
@@ -15,7 +15,7 @@
 #include <command.h>
 #include <rtc.h>
 
-#ifdef __I386__
+#if defined(__I386__) || defined(CONFIG_MALTA)
 #include <asm/io.h>
 #define in8(p) inb(p)
 #define out8(p, v) outb(v, p)