serial: bfin_5xx: move resources into board files

Rather than maintain Kconfig entries where people have to enter raw
numbers and hardcode lists of addresses/pins in the driver itself,
push it all to platform resources.  This lets us simplify the driver,
the Kconfig, and gives board porters greater flexibility.

In the process, we need to also start supporting the early platform
interface.  Not a big deal, but it causes the patch to be bigger than
a simple resource relocation.

All the Blackfin boards already have their resources updated and in
place for this change.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>