This actually makes use of the new dmesg class rather than the dmesg
functions. It touches a lot of files, but almost all of these changes
are code removal rather than code addition.

v5: - Fix dmesg handling in resume

Signed-off-by: Dylan Baker <baker.dylan.c@gmail.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu> (v4)