common: Drop init.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/m68k/cpu/mcf547x_8x/slicetimer.c b/arch/m68k/cpu/mcf547x_8x/slicetimer.c
index 885659e..c4988f9 100644
--- a/arch/m68k/cpu/mcf547x_8x/slicetimer.c
+++ b/arch/m68k/cpu/mcf547x_8x/slicetimer.c
@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <irq_func.h>
 
 #include <asm/timer.h>