build: install qmp-commands.txt

File is targeted for install, but is never installed.
Signed-off-by: NBruce Rogers <brogers@suse.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Makefile

@@ -272,6 +272,7 @@ endif
 install-doc: $(DOCS)
 	$(INSTALL_DIR) "$(DESTDIR)$(qemu_docdir)"
 	$(INSTALL_DATA) qemu-doc.html  qemu-tech.html "$(DESTDIR)$(qemu_docdir)"
+	$(INSTALL_DATA) QMP/qmp-commands.txt "$(DESTDIR)$(qemu_docdir)"
 ifdef CONFIG_POSIX
 	$(INSTALL_DIR) "$(DESTDIR)$(mandir)/man1"
 	$(INSTALL_DATA) qemu.1 qemu-img.1 "$(DESTDIR)$(mandir)/man1"