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>
diff --git a/src/soc/rockchip/rk3288/clock.c b/src/soc/rockchip/rk3288/clock.c
index 1b1c135..28c7a426 100644
--- a/src/soc/rockchip/rk3288/clock.c
+++ b/src/soc/rockchip/rk3288/clock.c
@@ -519,15 +519,15 @@
 		return -1;
 	}
 
-	no = div_round_up(VCO_MIN_KHZ, freq_khz);
+	no = DIV_ROUND_UP(VCO_MIN_KHZ, freq_khz);
 	if (ext_div) {
-		*ext_div = div_round_up(no, max_no);
-		no = div_round_up(no, *ext_div);
+		*ext_div = DIV_ROUND_UP(no, max_no);
+		no = DIV_ROUND_UP(no, *ext_div);
 	}
 
 	/* only even divisors (and 1) are supported */
 	if (no > 1)
-		no = div_round_up(no, 2) * 2;
+		no = DIV_ROUND_UP(no, 2) * 2;
 
 	vco_khz = freq_khz * no;
 	if (ext_div)