[j-nsp] Port mirroring issue

[Curtis Call]

> 
> While configuring the Port Mirroring on MX router (MPC 3D 16x 10GE) I
> am getting following log message:
> 
> 
> *chassisd[1396]: Ignoring unsupported port-mirror instance config on
> PIC:
> FPC 0 PIC 0*
> 

It looks like you are configuring the port-mirror instance in the chassis hierarchy under the PIC level instead of under the FPC level. MPCs need to be configured at the FPC level because, unlike on DPCs, there is not a one-to-one mapping from PIC to PFE.