initramfs-framework: rename files dir

Fixes:
ERROR: initramfs-framework-1.0-r4 do_fetch: Fetcher failure for URL: 'file://dmverity'. Unable to fetch URL from any source.

Signed-off-by: Armin Kuster <akuster808@gmail.com>

recipes-core/initrdscripts/initramfs-framework.inc

@@ -1,4 +1,4 @@
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS_prepend := "${THISDIR}/initramfs-framework-dm:"
 
 SRC_URI_append = "\
     file://dmverity \