Fix 8641HPCN problem with ld version 2.16

(Dot outside sections problem).

This fix is in the spirit of 807d5d73.
Signed-off-by: NJon Loeliger <jdl@freescale.com>

board/mpc8641hpcn/u-boot.lds

@@ -120,10 +120,12 @@ SECTIONS
   _edata  =  .;
   PROVIDE (edata = .);
 
+  . = .;
   __u_boot_cmd_start = .;
   .u_boot_cmd : { *(.u_boot_cmd) }
   __u_boot_cmd_end = .;
 
+  . = .;
   __start___ex_table = .;
   __ex_table : { *(__ex_table) }
   __stop___ex_table = .;