qcacld-3.0: Distribute credits amongst groups

1) When a group is created i.e. the first vdev is added to it,
assign all the credits to it.
2) When the second group is created, transfer some minimum credits
to it.
3) When a group is deleted, transfer its credits to the other group.

Change-Id: I0c5532033718b250ab0633b4da4e219c0315cac9
CRs-fixed: 2246206
2 files changed