Enable VA-API gallium frontend

lib/mesa/mk/libva_st/Makefile

@@ -0,0 +1,50 @@
+#	$OpenBSD: Makefile,v 1.1 2024/07/19 14:40:39 rsadowski Exp $
+
+.include <bsd.xconf.mk>
+
+LIB=	va_st
+
+NOPROFILE=
+
+SRCS=	buffer.c \
+	config.c \
+	context.c \
+	display.c \
+	image.c \
+	picture.c \
+	picture_av1.c \
+	picture_av1_enc.c \
+	picture_h264.c \
+	picture_h264_enc.c \
+	picture_hevc.c \
+	picture_hevc_enc.c \
+	picture_mjpeg.c \
+	picture_mpeg12.c \
+	picture_mpeg4.c \
+	picture_vc1.c \
+	picture_vp9.c \
+	postproc.c \
+	subpicture.c \
+	surface.c
+
+.include "../Makefile.inc"
+
+CFLAGS+=	${C_VIS_ARGS}
+CXXFLAGS+=	${CXX_VIS_ARGS}
+
+# XXX keep in sync with libva
+CFLAGS +=	-DVA_DRIVER_INIT_FUNC=__vaDriverInit_1_22
+CPPFLAGS +=	-DVA_DRIVER_INIT_FUNC=__vaDriverInit_1_22
+
+CPPFLAGS+=	-I${MESA_SRC}/src/gallium/frontends/va \
+		-I${MESA_SRC}/src/gallium/include \
+		-I${MESA_SRC}/src/gallium/auxiliary
+
+install:
+
+obj: _xenocara_obj
+
+.include <bsd.lib.mk>
+.include <bsd.xorg.mk>
+
+.PATH: ${MESA_SRC}/src/gallium/frontends/va