meta-yadro: os-release: fix build

Yocto now requires the files listed within `CONFFILES` also be included
to `FILES`.

Change-Id: I48617ee860b6eda06ac4aaa07b9b1bb7b368b5af
Signed-off-by: Alexander Filippov <a.filippov@yadro.com>
diff --git a/meta-yadro/recipes-core/os-release/os-release.bbappend b/meta-yadro/recipes-core/os-release/os-release.bbappend
index 7cd842a..756d440 100644
--- a/meta-yadro/recipes-core/os-release/os-release.bbappend
+++ b/meta-yadro/recipes-core/os-release/os-release.bbappend
@@ -126,5 +126,6 @@
 }
 
 CONFFILES:${PN} += " ${sysconfdir}/issue ${sysconfdir}/issue.net"
+FILES:${PN} += " ${sysconfdir}/issue ${sysconfdir}/issue.net"
 OS_RELEASE_FIELDS:append = " RELEASE PATCH_LEVEL"
 BB_DONT_CACHE = "1"