rtc: hym8563: fix invalid year calculation

Year field must be in BCD format, according to
hym8563 datasheet.

Due to the bug year 2016 became 2010.

Fixes: dcaf03849352 ("rtc: add hym8563 rtc-driver")
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-hym8563.c b/drivers/rtc/rtc-hym8563.c
index 097325d..b1b4746 100644
--- a/drivers/rtc/rtc-hym8563.c
+++ b/drivers/rtc/rtc-hym8563.c
@@ -144,7 +144,7 @@
 	 * it does not seem to carry it over a subsequent write/read.
 	 * So we'll limit ourself to 100 years, starting at 2000 for now.
 	 */
-	buf[6] = tm->tm_year - 100;
+	buf[6] = bin2bcd(tm->tm_year - 100);
 
 	/*
 	 * CTL1 only contains TEST-mode bits apart from stop,