build libmesa_util_sse41 on all archs

swrast_dri.so had an undefined reference to util_streaming_load_memcpy
on non-x86 archs.

Part of streaming-load-memcpy.c / libmesa_util_sse41.
When USE_SSE41 is not defined, memcpy() is used.

problem noticed at runtime on arm64 by mlarkin@
with and ok tb@

lib/mesa/mk/libGL/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.7 2023/01/29 12:20:31 jsg Exp $
+#	$OpenBSD: Makefile,v 1.8 2023/03/03 06:32:18 jsg Exp $
 
 .include <bsd.xconf.mk>
 
@@ -67,13 +67,9 @@ LDADD+=	-L${.CURDIR}/../libglapi/${__objdir} -lglapi \
 	${.CURDIR}/../libloader/${__objdir}/libloader.a \
 	${.CURDIR}/../libxmlconfig/${__objdir}/libxmlconfig.a \
 	${.CURDIR}/../libmesa_util/${__objdir}/libmesa_util.a \
-	${.CURDIR}/../libmesa_format/${__objdir}/libmesa_format.a
-
-.if ${WITH_SSE41} == "yes"
-LDADD+=${.CURDIR}/../libmesa_util_sse41/${__objdir}/libmesa_util_sse41.a
-.endif
-
-LDADD+=	-Wl,--gc-sections
+	${.CURDIR}/../libmesa_format/${__objdir}/libmesa_format.a \
+	${.CURDIR}/../libmesa_util_sse41/${__objdir}/libmesa_util_sse41.a \
+	-Wl,--gc-sections
 
 .if ${XENOCARA_BUILD_DRI3:L} == "yes"
 LDADD+=	${.CURDIR}/../libloader_dri3_helper/${__objdir}/libloader_dri3_helper.a