Start building sysrepo-ietf-alarms

The project also requires date library[1] but it was not running
correctly on our ARM. I had to patch the library with the workaround
from [2], hence the buildroot update.

[1] https://github.com/HowardHinnant/date
[2] https://github.com/HowardHinnant/date/issues/252

Change-Id: Ie82b8c9ea50b0198b024256ff81d67ba7344c190
diff --git a/package/Config.in b/package/Config.in
index 0ef80ea..a494e28 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -8,3 +8,4 @@
 source "$BR2_EXTERNAL_CZECHLIGHT_PATH/package/grub2-tools/Config.in"
 source "$BR2_EXTERNAL_CZECHLIGHT_PATH/package/reset-sysrepo/Config.in"
 source "$BR2_EXTERNAL_CZECHLIGHT_PATH/package/rousette/Config.in"
+source "$BR2_EXTERNAL_CZECHLIGHT_PATH/package/sysrepo-ietf-alarms/Config.in"