package/docker-containerd: add missing dependency on host-pkgconf

When libsseccomp support is enabled, docker-containerd uses pkg-config
to find libsseccomp, so we must depend on host-pkconf.

Fixes the following build issue, detected with per-package directory
support:

pkg-config: exec: "pkg-config": executable file not found in $PATH

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 14cbcbe2d4ba01754b745101b365f0e80c6c87d8)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/docker-containerd/docker-containerd.mk

@@ -19,7 +19,7 @@ DOCKER_CONTAINERD_BUILD_TARGETS = cmd/ctr cmd/containerd cmd/containerd-shim
 DOCKER_CONTAINERD_INSTALL_BINS = containerd containerd-shim
 
 ifeq ($(BR2_PACKAGE_LIBSECCOMP),y)
-DOCKER_CONTAINERD_DEPENDENCIES += libseccomp
+DOCKER_CONTAINERD_DEPENDENCIES += libseccomp host-pkgconf
 DOCKER_CONTAINERD_TAGS += seccomp
 endif