databases/grass8: check for omp.h on all architectures

databases/grass8/Makefile

@@ -109,16 +109,16 @@ PDAL_LIB_DEPENDS=	libpdal_base.so:math/pdal
 PGSQL_USES=		pgsql
 PGSQL_CONFIGURE_WITH=	postgres
 
+.if exists(/usr/include/omp.h)
+CONFIGURE_ARGS+=	--with-openmp
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if !defined (GRASS_INST_DIR)
 GRASS_INST_DIR=	${PORTNAME}${VER}
 .endif
 
-.if ${ARCH} != powerpc
-CONFIGURE_ARGS+=	--with-openmp
-.endif
-
 MANDIRS=	${PREFIX}/grass${VER}/docs/man/man1
 
 post-patch: