util: add common ARRAY_SIZE define

I want to use this in more places, so put it in util.h rather than
copying & pasting it into another file.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

convert-dtsv0-lexer.l

@@ -50,8 +50,6 @@ static int saw_hyphen; /* = 0 */
 static unsigned long long last_val;
 static char *last_name; /* = NULL */
 
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
-
 const struct {
 	const char *pattern;
 	int obase, width;

dtc.h

@@ -66,7 +66,6 @@ typedef uint32_t cell_t;
 #define strneq(a, b, n)	(strncmp((a), (b), (n)) == 0)
 
 #define ALIGN(x, a)	(((x) + (a) - 1) & ~((a) - 1))
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
 /* Data blobs */
 enum markertype {

util.h

@@ -24,6 +24,8 @@
  *                                                                   USA
  */
 
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
 static inline void __attribute__((noreturn)) die(const char *str, ...)
 {
 	va_list ap;