net/bnxt: allow configuration of a VNIC

net/bnxt: allow configuration of a VNIC

This patch adds APIs to allow configuration of a VNIC.
The functions alloc and free the Class of Service or COS and
Load Balance context corresponding to the VNIC in the chip.

New HWRM calls:
bnxt_hwrm_vnic_ctx_alloc:
	Used to allocate COS/Load Balance context of VNIC
bnxt_hwrm_vnic_ctx_free:
	Used to free COS/Load Balance context of VNIC

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Stephen Hurd <stephen.hurd@broadcom.com>
Reviewed-by: David Christensen <david.christensen@broadcom.com>