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/commonlib/include/commonlib/helpers.h

@@ -36,7 +36,6 @@
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif
 #define ABS(a) (((a) < 0) ? (-(a)) : (a))
-#define CEIL_DIV(a, b)  (((a) + (b) - 1) / (b))
 #define IS_POWER_OF_2(x)  (((x) & ((x) - 1)) == 0)
 #define DIV_ROUND_UP(x, y)  (((x) + (y) - 1) / (y))
 /*