net/bnxt: allocate rings and groups

net/bnxt: allocate rings and groups

Add a top level functions to initialize ring groups, and functions
to allocate and free all the rings via HWRM.

A ring group is identified by an index. It consists of Rx or Tx ring id,
completion ring id and a statistics context. Once a ring group is
initialized, use this group index while creating the rings in the ASIC
using the appropriate HWRM API added via earlier patches.

Functions added:
bnxt_free_cp_ring
	Calls the HWRM function generic ring free with arguments specific
	to a completion ring and sanitizes the host completion structure
bnxt_free_all_hwrm_rings
	Frees all the HWRM allocated hardware rings
bnxt_free_all_hwrm_resources
	Frees all the resources allocated via the HRM in the hardware
bnxt_alloc_hwrm_rings
	Allocates all the HWRM rings needed in the current configuration

This should be the last functionality needed to add start/stop
device operations.

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>