common: Drop asm_offsets.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/asm-offsets.c b/lib/asm-offsets.c
index 2617513..b17651e 100644
--- a/lib/asm-offsets.c
+++ b/lib/asm-offsets.c
@@ -12,6 +12,7 @@
  */
 
 #include <common.h>
+#include <asm-offsets.h>
 
 #include <linux/kbuild.h>