arm: ls1021atwr: Rework local commands to not be included in SPL

arm: ls1021atwr: Rework local commands to not be included in SPL

Move some of the code for the "lane_bank" and "cpld" code local
commands so that they are not built for SPL as they can only be
used in full U-Boot.  This means we can mark a few functions as
static as well now.

Cc: Alison Wang <alison.wang@freescale.com>
Cc: Sumit Garg <sumit.garg@nxp.com>
Cc: York Sun <york.sun@nxp.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Alison Wang <alison.wang@nxp.com>
Tested-by: Alison Wang <alison.wang@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>