Enable proper configuration of CESA MBUS windows

For all Marvell devices, MBUS windows configuration is done
in a common place. Only CESA was an exception, so move its
related code from driver to mv_common.c. This way it uses
same proper DRAM information, same as all other interfaces
instead of parsing DT /memory node directly.

Submitted by: Marcin Wojtas <mw@semihalf.com>
Obtained from: Semihalf
Sponsored by: Stormshield
Reviewed by: loos
Differential revision: https://reviews.freebsd.org/D10723