Add support for allmulticast flag

[mlguerrero12]

This allows users to set the allmulticast mode for a VF.

[coveralls]

Pull Request Test Coverage Report for Build 5323513802

• 41 of 61 (67.21%) changed or added relevant lines in 4 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+1.4%) to 39.848%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/config/config.go	9	11	81.82%
pkg/utils/mocks/netlink_manager_mock.go	20	24	83.33%
pkg/utils/netlink_manager.go	0	6	0.0%
pkg/sriov/sriov.go	12	20	60.0%
<!--	Total:	41	61	67.21%	-->

Files with Coverage Reduction	New Missed Lines	%
pkg/utils/mocks/netlink_manager_mock.go	1	80.12%
<!--	Total:	1		-->

Totals
Change from base Build 5210643953:	1.4%
Covered Lines:	473
Relevant Lines:	1187

---

💛 - Coveralls

[mlguerrero12]

@SchSeba, @adrianchiris, could you please take a look a this?

[cgoncalves]

Add new parameter to docs/configuration-reference.md

Also to README.md

[mlguerrero12]

@cgoncalves, done

[mlguerrero12]

Thank you @SchSeba, I addressed your comment.

[SchSeba]

Hi @mlguerrero12 can you please fix the test?

[mlguerrero12]

Hi @Eoghan1232, could you please review this?

[mlguerrero12]

@adrianchiris, I addressed your comments. Thank you.

[adrianchiris]

@adrianchiris, I addressed your comments. Thank you.

thanks for addressing !

[adrianchiris]

@mlguerrero12 @SchSeba i see that tuning CNI supports setting all multicast.

https://github.com/containernetworking/cni.dev/blob/main/content/plugins/current/meta/tuning.md

started to think if we really need it part of sriov-cni ? as all multicast is general for netdev no nessecarily for VF and tuning CNI already supports it.