mgr/cephadm: lower log level when logging about related services

mgr/cephadm: lower log level when logging about related services

This was recently added in https://github.com/ceph/ceph/commit/088d2c4205c599a7d4f2ce4de8e2af8e129adac8
and seems to work fine, but logging these things at info
level spams the log as every single service every serve
loop iteration is reporting on whether it has related
daemons. This changes it to only log when it finds
related daemons or when it prefers a host due to those
related daemons, and do both of those at only debug level.

Signed-off-by: Adam King <adking@redhat.com>
(cherry picked from commit 3693544e56b2480547c21575ab70ec2e67977b94)