md: rename some drivers/md/ files to have an "md-" prefix

Motivated by the desire to illiminate the imprecise nature of
DM-specific patches being unnecessarily sent to both the MD maintainer
and mailing-list.  Which is born out of the fact that DM files also
reside in drivers/md/

Now all MD-specific files in drivers/md/ start with either "raid" or
"md-" and the MAINTAINERS file has been updated accordingly.

Shaohua: don't change module name

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 786ec9e..693602f 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -18,9 +18,12 @@
 dm-cache-smq-y   += dm-cache-policy-smq.o
 dm-era-y	+= dm-era-target.o
 dm-verity-y	+= dm-verity-target.o
-md-mod-y	+= md.o bitmap.o
+md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
 dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
+linear-y	+= md-linear.o
+multipath-y	+= md-multipath.o
+faulty-y	+= md-faulty.o
 
 # Note: link order is important.  All raid personalities
 # and must come before md.o, as they each initialise