drivers/pc80/mc146818rtc: Enable RTC reset on power loss

If function cmos_init() was called with parameter invalid
set, this indicates, that the caller has found a power
loss event in the RTC registers. In this case, we need to
load the default date and time because it can be corrupted.

Change-Id: Ib8d58a14da0182ceb8167e67440a0f1ea2a20eb7
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: http://review.coreboot.org/8373
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: build bot (Jenkins)

src/drivers/pc80/mc146818rtc.c

@@ -86,7 +86,7 @@ static void cmos_set_checksum(int range_start, int range_end, int cks_loc)
 #ifndef __SMM__
 void cmos_init(bool invalid)
 {
-	bool cmos_invalid = false;
+	bool cmos_invalid = invalid;
 	bool checksum_invalid = false;
 	bool clear_cmos;
 	size_t i;