x11/libxkbcommon: Add dep on xkeyboard-config

Add a run time dependency on x11/xkeyboard-config in x11/libxkbcommon.
While not strictly necessary, this is recommended upstream, since almost all
uses of libxkbcommon also needs xkeyboard-config.  This is similar to how it
is done in other distributions.

This solves issues when graphics/xpdf4 is installed without a desktop or
graphical environment, as well as other places.

PR:		229127
Reported by:	Bertrand Petit
Suggested by:	tobik

x11/libxkbcommon/Makefile

@@ -2,6 +2,7 @@
 
 PORTNAME=	libxkbcommon
 PORTVERSION=	0.8.0
+PORTREVISION=	1
 CATEGORIES=	x11
 MASTER_SITES=	http://xkbcommon.org/download/
 
@@ -11,6 +12,8 @@ COMMENT=	Keymap handling library for toolkits and window systems
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
+RUN_DEPENDS=	xkeyboard-config>0:x11/xkeyboard-config
+
 XORG_CAT=	lib
 USES=		gmake bison tar:xz