[sparc64/base-gcc] Fix build of graphics/colord-gtk

Adding -L${X11BASE}/lib to CFLAGS fixes the build on sparc64 (And presumably
other base-gcc architectures).

No revision bump since it hasn't built on sparc64 and shouldn't make
a difference to non-sparc64.

ok?

(cc maintainer)

--Kurt

Index: Makefile
===================================================================
RCS file: /cvs/ports/graphics/colord-gtk/Makefile,v
retrieving revision 1.22
diff -u -p -r1.22 Makefile
--- Makefile 10 Jul 2019 21:01:27 -0000 1.22
+++ Makefile 25 Mar 2020 02:32:47 -0000
@@ -38,4 +38,6 @@ CONFIGURE_ARGS= -Ddocs=false \
# XXX require docbook-xsl-nsl
CONFIGURE_ARGS += -Dman=false

+CFLAGS += -L${X11BASE}/lib
+
.include <bsd.port.mk>