kmcoge5ne: Move BFTIC3 CONFIG references to their usage

We only reference CONFIG_SYS_BFTIC3_BASE in one location.  Move the
comment to where we reference it, and use the value directly.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Holger Brunck <holger.brunck@hitachienergy.com>
Reviewed-by: Heiko Schocher <hs@denx.de>