zebra: Add uptime to `show evpn mac vni ... detail`

zebra: Add uptime to `show evpn mac vni ... detail`

Add the uptime a mac entry has been in the system.

New Output:

eva# show evpn mac vni all detail

VNI 1000 #MACs (local and remote) 16

MAC: 4e:2d:f3:75:ff:db
 ESI: 03:44:38:39:ff:ff:01:00:00:02
 Intf: hostbond2(10) VLAN: 1000
 Sync-info: neigh#: 0 peer-active
 Local Seq: 0 Remote Seq: 0
 Uptime: 00:00:28
 Neighbors:
    No Neighbors

MAC: 7a:a4:f2:30:dd:5d
 ESI: 03:44:38:39:ff:ff:01:00:00:01
 Intf: hostbond1(9) VLAN: 1000
 Sync-info: neigh#: 0 peer-active
 Local Seq: 0 Remote Seq: 0
 Uptime: 00:00:28
 Neighbors:
    No Neighbors

MAC: 66:9e:d7:3a:f1:f1
 Remote VTEP: 192.168.100.18
 Sync-info: neigh#: 0
 Local Seq: 0 Remote Seq: 0
 Uptime: 00:00:26
 Neighbors:
    45.0.0.5 Active
    fe80::649e:d7ff:fe3a:f1f1 Active

MAC: 26:f1:bd:5f:e1:77
 Remote ES: 03:44:38:39:ff:ff:02:00:00:02
 Sync-info: neigh#: 0
 Local Seq: 0 Remote Seq: 0
 Uptime: 00:00:23
 Neighbors:
    No Neighbors

MAC: 16:80:eb:c4:43:6d
 ESI: 03:44:38:39:ff:ff:01:00:00:01
 Intf: hostbond1(9) VLAN: 1000
 Sync-info: neigh#: 0 peer-active
 Local Seq: 0 Remote Seq: 0
 Uptime: 00:00:28
 Neighbors:
    No Neighbors

MAC: 00:00:00:00:00:22
 Remote ES: 03:44:38:39:ff:ff:02:00:00:02
 Sync-info: neigh#: 0
 Local Seq: 0 Remote Seq: 0
 Uptime: 00:00:26
 Neighbors:
    No Neighbors

Signed-off-by: Donald Sharp <sharpd@nvidia.com>