ice: factor VF variables to separate structure

We maintain a number of values for VFs within the ice_pf structure. This
includes the VF table, the number of allocated VFs, the maximum number
of supported SR-IOV VFs, the number of queue pairs per VF, the number of
MSI-X vectors per VF, and a bitmap of the VFs with detected MDD events.

We're about to add a few more variables to this list. Clean this up
first by extracting these members out into a new ice_vfs structure
defined in ice_virtchnl_pf.h

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>