Register librt and usign as installed with opkg

opkg-feed/installer/openwrt-sdxlemur-skel/usr/lib/opkg/info/librt.control

@@ -0,0 +1,14 @@
+Package: librt
+Version: 1.2.3-4
+Depends: libpthread
+Source: package/libs/toolchain
+SourceName: librt
+License: GPL-3.0-with-GCC-exception
+Section: libs
+SourceDateEpoch: 1690286952
+Status: unknown hold not-installed
+Essential: yes
+Maintainer: Felix Fietkau <nbd@nbd.name>
+Architecture: arm_cortex-a7_neon-vfpv4
+Installed-Size: 124
+Description:  POSIX.1b RealTime extension library

opkg-feed/installer/openwrt-sdxlemur-skel/usr/lib/opkg/info/librt.prerm

@@ -0,0 +1,4 @@
+#!/bin/sh
+[ -s ${IPKG_INSTROOT}/lib/functions.sh ] || exit 0
+. ${IPKG_INSTROOT}/lib/functions.sh
+default_prerm $0 $@

opkg-feed/installer/openwrt-sdxlemur-skel/usr/lib/opkg/status

@@ -293,3 +293,17 @@ Status: install user installed
 Architecture: arm_cortex-a7_neon-vfpv4
 Installed-Time: 1733796300
 
+Package: usign
+Version: 2020-05-23-f1f65026-1
+Depends: libc, libubox20220515
+Status: install user installed
+Architecture: arm_cortex-a7_neon-vfpv4
+Installed-Time: 1733796301
+
+Package: librt
+Version: 1.2.3-4
+Depends: libpthread
+Status: install user installed
+Architecture: arm_cortex-a7_neon-vfpv4
+Installed-Time: 1733796302
+