Make div_round_up() correct for divisors that are not a power of 2

The current div_round_up() implementation relies on round_up() which
only works correctly for boundaries that are a power of 2. It is
documented as such, but this still seems dangerously easy to overlook,
especially since many other environments (e.g. the Linux kernel) have a
similar macro without these limitations.

There is a different way to calculate this that can deal with all kinds
of divisors without other drawbacks, so let's just use that instead.

Change-Id: Id382736683f5d4e880ef00c53cfa23a2f9208440
Signed-off-by: Julius Werner <jwerner@chromium.org>

include/lib/utils_def.h

@@ -24,6 +24,11 @@
  */
 #define DIV_ROUND_UP_2EVAL(n, d)	(((n) + (d) - 1) / (d))
 
+#define div_round_up(val, div) __extension__ ({	\
+	__typeof__(div) _div = (div);		\
+	((val) + _div - 1) / _div;		\
+})
+
 #define MIN(x, y) __extension__ ({	\
 	__typeof__(x) _x = (x);		\
 	__typeof__(y) _y = (y);		\
@@ -55,11 +60,6 @@
 #define round_down(value, boundary)		\
 	((value) & ~round_boundary(value, boundary))
 
-#define div_round_up(val, div) __extension__ ({	\
-	__typeof__(div) _div = (div);		\
-	round_up((val), _div)/_div;		\
-})
-
 /*
  * Evaluates to 1 if (ptr + inc) overflows, 0 otherwise.
  * Both arguments must be unsigned pointer values (i.e. uintptr_t).