Add aarch64 pkg-config binary

bin/aarch64-unknown-redox-pkg-config

+#!/usr/bin/env bash
+
+export PKG_CONFIG_SYSROOT_DIR="${COOKBOOK_RECIPE}/sysroot"
+export PKG_CONFIG_LIBDIR="${PKG_CONFIG_SYSROOT_DIR}/lib/pkgconfig"
+export PKG_CONFIG_PATH="${PKG_CONFIG_SYSROOT_DIR}/share/pkgconfig"
+
+exec pkg-config --static "$@"