Assist getting more ports working on AMD64 by obeying the

Ports Collection documentation and use 'ARCH' rather than 'MACHINE_ARCH'.

databases/sqlite3/Makefile

@@ -54,7 +54,7 @@ USE_LIBTOOL_VER=	13
 GNU_CONFIGURE=	YES
 USE_REINPLACE=	YES
 CONFIGURE_ARGS=	--prefix=${PREFIX} --with-hints=freebsd.hints
-CONFIGURE_TARGET=	--build=${MACHINE_ARCH}-portbld-freebsd${OSREL}
+CONFIGURE_TARGET=	--build=${ARCH}-portbld-freebsd${OSREL}
 ALL_TARGET=	all
 
 INSTALLS_SHLIB=	YES