us.intl.acc.kbd: add it to Makefile

This keyboard was implemented but wasn't actually installed to the
system.

Fixes: a049678039
Discussed with: imp
MFC after: 1 day
Relnotes: yes

share/vt/keymaps/Makefile

@@ -80,6 +80,7 @@ FILES=	INDEX.keymaps \
 	uk.kbd \
 	uk.macbook.kbd \
 	us.acc.kbd \
+	us.intl.acc.kbd \
 	us.ctrl.kbd \
 	us.dvorak.kbd \
 	us.dvorakl.kbd \