post: remove #warning for kirkwood CPUs

Since commit 96f5c4b2 the needed functions (get_ticks() and get_tbclk() )
are defined for kirkwood CPUs as well. This warning is then not relevant
anymore.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Holger Brunck <holger.brunck@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>
cc: Albert Aribaud <albert.u.boot@aribaud.net>

post/post.c

@@ -495,8 +495,7 @@ void post_reloc(void)
  */
 unsigned long post_time_ms(unsigned long base)
 {
-#if defined(CONFIG_PPC) || defined(CONFIG_BLACKFIN) || \
-    (defined(CONFIG_ARM) && !defined(CONFIG_KIRKWOOD))
+#if defined(CONFIG_PPC) || defined(CONFIG_BLACKFIN) || defined(CONFIG_ARM)
 	return (unsigned long)lldiv(get_ticks(), get_tbclk() / CONFIG_SYS_HZ)
 		- base;
 #else