Bump buidlroot version to 2018.02.6

bsp/buildroot/package/pkg-autotools.mk

@@ -199,9 +199,9 @@ define $(2)_CONFIGURE_CMDS
 		--disable-documentation \
 		--with-xmlto=no \
 		--with-fop=no \
-		--disable-dependency-tracking \
+		$$(if $$($$(PKG)_OVERRIDE_SRCDIR),,--disable-dependency-tracking) \
 		--enable-ipv6 \
-		$$(DISABLE_NLS) \
+		$$(NLS_OPTS) \
 		$$(SHARED_STATIC_LIBS_OPTS) \
 		$$(QUIET) $$($$(PKG)_CONF_OPTS) \
 	)
@@ -220,7 +220,7 @@ define $(2)_CONFIGURE_CMDS
 	$$($$(PKG)_CONF_ENV) \
 	CONFIG_SITE=/dev/null \
 	./configure \
-		--prefix="$$(HOST_DIR)/usr" \
+		--prefix="$$(HOST_DIR)" \
 		--sysconfdir="$$(HOST_DIR)/etc" \
 		--localstatedir="$$(HOST_DIR)/var" \
 		--enable-shared --disable-static \
@@ -232,7 +232,7 @@ define $(2)_CONFIGURE_CMDS
 		--disable-debug \
 		--with-xmlto=no \
 		--with-fop=no \
-		--disable-dependency-tracking \
+		$$(if $$($$(PKG)_OVERRIDE_SRCDIR),,--disable-dependency-tracking) \
 		$$(QUIET) $$($$(PKG)_CONF_OPTS) \
 	)
 endef