base: Introduce wayland-cdi service

This change introduces logic to generate a CDI definition for the Weston
display created at boot. With CDI enabled in a container runtime like
Docker, you could run Wayland apps with a command like:
running:
```
 docker run --rm -it --device=org.wayland/display=wayland-1 ubuntu
```

Signed-off-by: Andy Doan <[email protected]>

meta-lmp-base/recipes-containers/wayland-cdi/files/wayland-cdi-generate

@@ -0,0 +1,47 @@
+#!/bin/sh
+
+cditmp="/run/cdi/.wayland.yaml.tmp"
+
+mkdir -p /run/cdi
+cat >${cditmp} <<EOF
+cdiVersion: "0.6.0"
+kind: org.wayland/display
+devices:
+EOF
+
+mounts=""
+for x in `find /run/user -mindepth 2 -maxdepth 2 -type s -name wayland-\*` ; do
+	echo Found Wayland instance: $x
+	found=1
+	xdg_dir="$(dirname $x)"
+	display_name="$(basename $x)"
+	mounts="${mounts} ${xdg_dir}"
+	cat >>${cditmp} <<EOF
+- name: ${display_name}
+  containerEdits:
+    env:
+    - WAYLAND_DISPLAY=${display_name}
+    - XDG_RUNTIME_DIR=${xdg_dir}
+EOF
+done
+
+if [ -n "${mounts}" ] ; then
+	cat >>${cditmp} <<EOF
+containerEdits:
+  mounts:
+EOF
+
+	for x in ${mounts} ; do
+		cat >>${cditmp} <<EOF
+  - type: bind
+    hostPath: ${x}
+    containerPath: ${x}
+    options:
+    - rbind
+    - rprivate
+EOF
+	done
+	mv ${cditmp} /run/cdi/wayland.yaml
+else
+	rm ${cditmp}
+fi

meta-lmp-base/recipes-containers/wayland-cdi/files/wayland-cdi.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=CDI device entry generator for Wayland
+After=weston.service
+Before=docker.service
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/wayland-cdi-generate
+RemainAfterExit=yes
+
+[Install]
+WantedBy=weston.service
+RequiredBy=docker.service

meta-lmp-base/recipes-containers/wayland-cdi/wayland-cdi_0.1.bb

@@ -0,0 +1,24 @@
+SUMMARY = "Sets up a CDI device entry for the Wayland display"
+LICENSE = "MIT"
+LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
+
+inherit allarch systemd
+
+RDEPENDS:${PN} = "systemd"
+
+SRC_URI = "file://wayland-cdi.service \
+    file://wayland-cdi-generate \
+"
+
+PACKAGE_ARCH = "${MACHINE_ARCH}"
+
+SYSTEMD_SERVICE:${PN} = "wayland-cdi.service"
+SYSTEMD_AUTO_ENABLE:${PN} = "enable"
+
+do_install() {
+	install -d ${D}${bindir}
+	install -m 0755 ${WORKDIR}/wayland-cdi-generate ${D}${bindir}/wayland-cdi-generate
+
+	install -d ${D}${systemd_system_unitdir}
+	install -m 0644 ${WORKDIR}/wayland-cdi.service ${D}${systemd_system_unitdir}
+}