src: Remove duplicated round up function

This removes CEIL_DIV and div_round_up() altogether and
replace it by DIV_ROUND_UP defined in commonlib/helpers.h.

Change-Id: I9aabc3fbe7834834c92d6ba59ff0005986622a34
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/29847
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/cpu/x86/tsc/delay_tsc.c

@@ -83,7 +83,7 @@ static unsigned long calibrate_tsc_with_pit(void)
 		if (end.lo <= CALIBRATE_DIVISOR)
 			goto bad_ctc;
 
-		return CEIL_DIV(end.lo, CALIBRATE_DIVISOR);
+		return DIV_ROUND_UP(end.lo, CALIBRATE_DIVISOR);
 	}
 
 	/*