Make validation in Marvell mv_common.c generic

Validate only drivers used by given platform.
Pointers to validation function
are added to soc_node_spec structure.

Submitted by: Rafal Kozik <rk@semihalf.com>
Reviewed by: andrew
Obtained from: Semihalf
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D14737