ice: initialize pf->supported_rxdids immediately after loading DDP

ice: initialize pf->supported_rxdids immediately after loading DDP

The pf->supported_rxdids field is used to populate the list of valid RXDIDs
that a VF may use when negotiating VIRTCHNL_VF_OFFLOAD_RX_FLEX_DESC.

The set of supported RXDIDs is dependent on the DDP, and can be read from
the GLXFLXP_RXDID_FLAGS register. The PF needs to send this list to the
VF upon receiving the VIRTCHNL_OP_GET_SUPPORTED_RXDIDs. It also needs to
use this list to validate the requested descriptor ID from the VF when
programming the Rx queues.

A future update to support VF live migration will also want to validate
that the target VF can support the same descriptor ID when migrating.

Currently, pf->supported_rxdids is initialized inside the
ice_vc_query_rxdid() function. This means that it is only ever initialized
if at least one VF actually tries to negotiate
VIRTCHNL_VF_OFFLOAD_RX_FLEX_DESC. It is also unnecessarily re-initialized
every time the VF loads and requests the descriptor list. This worked
before because the PF only checks pf->suppported_rxdids when programming
the Rx queue if the VF actually negotiates the
VIRTCHNL_VF_OFFLOAD_RX_FLEX_DESC feature.

This will be problematic for VF live migration. We need the list of
supported Rx descriptor IDs when migrating. It is possible that no VF on
the target PF has ever actually issued a VIRTCHNL_OP_GET_SUPPORTED_RXDIDs.

Refactor the driver to initialize pf->supported_rxdids during driver
initialization after the DDP is loaded. This is simpler, avoids unnecessary
duplicate work, and avoids issues with the live migration process.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>