ice: Consolidate VSI state and flags

struct ice_vsi has two fields, state and flags which seem to
be serving the same purpose. Consolidate them into one field
'state'.

enum ice_state is used to represent state information of the PF.
While some of these enum values can be use to represent VSI state,
it makes more sense to represent VSI state with its own enum. So
derive a new enum ice_vsi_state from ice_vsi_flags and ice_state
and use it. Also rename enum ice_state to ice_pf_state for clarity.

Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>