RDMA/irdma: Refactor DCB bits in prep for DSCP support

Rename dcb flag to dcb_vlan_mode in irdma_device struct.  Add a new helper
function, irdma_set_qos_info, to set the VSI QoS information passed by the
PCI driver.

Link: https://lore.kernel.org/r/20220202191921.1638-3-shiraz.saleem@intel.com


Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>