Enhancement: parallelize nodes update

[AhmedGrati]

What would you like to be added:
Currently, we are updating nodes in a sequential way.

node-feature-discovery/pkg/nfd-master/nfd-master.go

Lines 295 to 306 in 821e042

	// TODO: we might want to update multiple nodes in parallel
	if updateAll {
	if err := m.nfdAPIUpdateAllNodes(); err != nil {
	klog.Error(err)
	}
	} else {
	for nodeName := range updateNodes {
	if err := m.nfdAPIUpdateOneNode(nodeName); err != nil {
	klog.Error(err)
	}
	}
	}

I think that we can optimize this step by parallelizing this process.

Why is this needed:
Optimization of updating nodes process, in terms of execution time.

[AhmedGrati]

If relevant, I can work on it.

[marquiz]

Thanks @AhmedGrati for the proposal. I think this would be a good improvement 👍 Just need to figure out a reasonable default for the parallelism

[AhmedGrati]

/assign