initramfs-framework: Add dmverity module

Add 'initramfs-module-dmverity' as an extension to poky upstream
provided initramfs-framework suite via matchingly named bbappend file.

Together with pre-existing 'initramfs-module-udev' this module can be
used to facilitate dm-verity rootfs mounting from initramfs context
that is bundled with Linux kernel.

Signed-off-by: Niko Mauno <niko.mauno@vaisala.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

recipes-core/initrdscripts/initramfs-framework_1.0.bbappend

@@ -0,0 +1,16 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+
+SRC_URI_append = "\
+    file://dmverity \
+"
+
+do_install_append() {
+    # dm-verity
+    install ${WORKDIR}/dmverity ${D}/init.d/80-dmverity
+}
+
+PACKAGES_append = " initramfs-module-dmverity"
+
+SUMMARY_initramfs-module-dmverity = "initramfs dm-verity rootfs support"
+RDEPENDS_initramfs-module-dmverity = "${PN}-base"
+FILES_initramfs-module-dmverity = "/init.d/80-dmverity"