Add missing files to Debian DKMS package

Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Umer Saleem <usaleem@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Damiano Albani <damiano.albani@gmail.com>
Closes #14887
Closes #14889

contrib/debian/rules.in

@@ -7,8 +7,8 @@ NAME := $(shell awk '$$1 == "Name:" { print $$2; }' META)
 LINUX_MIN  := $(shell awk '/Linux-Minimum:/{print $$2}' META)
 LINUX_NEXT := $(shell awk -F'[ .]' '/Linux-Maximum:/{print $$2 "." $$3+1}' META)
 
-DKMSFILES := module include config zfs.release.in autogen.sh META AUTHORS \
-		COPYRIGHT LICENSE README.md
+DKMSFILES := module include config zfs.release.in autogen.sh copy-builtin META AUTHORS \
+		COPYRIGHT LICENSE README.md CODE_OF_CONDUCT.md NEWS NOTICE RELEASES.md
 
 ifndef KVERS
 KVERS=$(shell uname -r)