ice: Fix and refactor Rx queue disable for VFs

Currently when a VF driver sends the PF a request to disable Rx queues
we will disable them one at a time, even if the VF driver sent us a
batch of queues to disable. This is causing issues where the Rx queue
disable times out with LFC enabled. This can be improved by detecting
when the VF is trying to disable all of its queues.

Also remove the variable num_qs_ena from the ice_vf structure as it was
only used to see if there were no Rx and no Tx queues active. Instead
add a function that checks if both the vf->rxq_ena and vf->txq_ena
bitmaps are empty.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>