'show bgp device-global' on multi-asic

[colintle]

What I did

• 'show bgp device-global' now works with multi-asic

How I did it

I modified the functionality for 'show bgp device-global'.

How to verify it

I tested on virtual T2-chassis with multi-asic and wrote UT for it.

Previous command output (if the output of a command-line utility has changed)

No output for multi-asic

New command output (if the output of a command-line utility has changed)

'show bgp device-global'

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: colintle / name: Colin Le (ec3c9484ca08cb84a7bae0f1b54669a9f3f8f9e2, 315b0ac7562c23bd28cfa8bc872c5183fc72abb7, d05ad24fefcfe4ed7b871a4fc54650292bddf1cc, fb6a596140f02783187525fcfa23ae490dbf6d1b, a9f3f0a0181442adeb4600a17bb6711b05448578, f85a082a1f832eb328718e6f7e8acd0b5bfb27eb, abdb648445e77b64a319162313f8c7da8fe3df97, 883cecbd6a096381f7a96232d1808b90d22a18e0, dae0ee2fc91df55d62148ac9111be99befc839fb, 1ac41655edde6a631fdd7a222b7a754a0c9ddb0f, babe748564d61a6ae7b11f222644f1290d8f298d, b9e974f2bba17d347e1123ade4d86a7603e06cfe, 1e1bfd443dbd4a566fe54f1bc7ff95929d474bc8, a898c34123d1d1f8612cdc681478a0ffedec1741, 0fe14db8f8260424c8fe1050f6b764f7b4ab7454, 5994f05d9984e1249bf0da01972ac61855d5aabf, 60047a03eee31d7a8ed09de006bdd0944706c2a4)