configs: remove redundant comment sections

mv-common.h and mv-plug-common.h still had comments delimiting sections
of configuration options that have all been moved to Kconfig by previous
treewide efforts. Remove the redundant comment sections.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>