Linux 4.4.173

BugLink: https://bugs.launchpad.net/bugs/1818803Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

Makefile

 VERSION = 4
 PATCHLEVEL = 4
-SUBLEVEL = 172
+SUBLEVEL = 173
 EXTRAVERSION =
 NAME = Blurry Fish Butt