graphics/gle: Fix build with llvm16

- Add LICENSE GPLv2
- Pet portclippy
- Add missing USE_XORG=xext reported by poudriere testport

Approved by:	portmgr (blanket)
Sponsored by:	The FreeBSD Foundation

graphics/gle/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	gle
 PORTVERSION=	3.1.0
-PORTREVISION=	8
+PORTREVISION=	9
 CATEGORIES=	graphics
 MASTER_SITES=	SF/${PORTNAME}/${PORTNAME}/${PORTNAME}-${PORTVERSION}\
 		http://linas.org/gle/pub/ \
@@ -11,15 +11,26 @@ MAINTAINER=	ports@dclg.ca
 COMMENT=	GL Tubing and Extrusion Library
 WWW=		https://linas.org/gle/
 
+LICENSE=	GPLv2
+LICENSE_FILE=	${WRKSRC}/COPYING
+
 USES=		gl libtool xorg
-USE_XORG=	ice xt xmu
 USE_GL=		glut
 USE_LDCONFIG=	yes
+USE_XORG=	ice xext xmu xt
+
 GNU_CONFIGURE=	yes
+
 LIBS+=		-L${LOCALBASE}/lib -lXext
 
 OPTIONS_DEFINE=	DOCS
 
+.include <bsd.port.options.mk>
+
+.if ${OPSYS} == FreeBSD && ${OSVERSION} >= 1400091
+CFLAGS+=	-Wno-error=incompatible-function-pointer-types
+.endif
+
 post-patch:
 .for file in ex_angle.c ex_cut_round.c ex_raw.c extrude.c round_cap.c segment.c texgen.c
 	@${REINPLACE_CMD} -e "s/malloc.h/stdlib.h/g" ${WRKSRC}/src/${file}