#### Why I did it
Create a target for delayed service timers. Few services in sonic have delayed to speed up the bring up of the system and essential services. However there is no way to track when they start. This will be a problem when executing config reload as config reload expects all services to be up. Hence grouped all the timers that trigger the delayed services under one target so that they could be tracked in 'config reload' command
#### How I did it
Created delay.target service and add created dependency on the delayed targets.
- Why I did it
Group all SONiC services together and able to manage them together. Will be used in config reload command as much simpler and generic way to restart services.
- How I did it
Add services to sonic.target
- How to verify it
Together with Azure/sonic-utilities#1199
config reload -y
Signed-off-by: Stepan Blyshchak <stepanb@nvidia.com>
management framework provides management plane services like rest and
CLI which is not needed right after boot, instead by delaying this
service we give some more CPU for data plane and control plane services
on fast/warm boot.
Signed-off-by: Stepan Blyschak <stepanb@nvidia.com>