[PATCH 2/3] udev.eclass: add udev_hwdb_reload function

reload the udev hardware database using the `systemd-hwdb update`
command. The `udevadm hwdb` has been deprecated upstream.

See-also: https://github.com/systemd/systemd/commit/f8717d2a723cf594617c3acb7e90992c881a3280
Signed-off-by: Lukas Schmelting <[email protected]>
---
 eclass/udev.eclass | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/eclass/udev.eclass b/eclass/udev.eclass
index 7d1c213fa643..1690f7dd16cb 100644
--- a/eclass/udev.eclass
+++ b/eclass/udev.eclass
@@ -130,3 +130,20 @@ udev_reload() {
 }
 
 fi
+
+# @FUNCTION: udev_hwdb_reload
+# @DESCRIPTION:
+# Update the udev hardware database.
+# Should be called from pkg_postinst and pkg_postrm in packages installing hwdb
+# files.
+udev_hwdb_reload() {
+	if [[ -n ${ROOT} ]]; then
+		return 0
+	fi
+
+	if [[ -d ${ROOT}/run/udev ]]; then
+		ebegin "Running systemd-hwdb update, to update the binary hardware database"
+		systemd-hwdb update --root "${ROOT}"
+		eend $?
+	fi
+}
-- 
2.53.0