rtc: goldfish: allow building on more than MIPS

Goldfish can be ARM or x86, allow building the driver for more than just
MIPS.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
diff --git a/drivers/rtc/rtc-goldfish.c b/drivers/rtc/rtc-goldfish.c
index 23301e1..3fbd271 100644
--- a/drivers/rtc/rtc-goldfish.c
+++ b/drivers/rtc/rtc-goldfish.c
@@ -16,6 +16,7 @@
 
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/rtc.h>