net/bnxt: add ring alloc/free

net/bnxt: add ring alloc/free

Add HWRM API calls to allocate and free TX, RX and Completion rings
in the hardware along with the associated structs and definitions.

This informs the hardware of how the specific rings were set up in the
host and allocates them in the HWRM, setting up the doorbell registers
etc. as needed, returning an ID for the ring.

Basic ring alloc/free calls:
bnxt_hwrm_ring_alloc
	This command allocates and does basic preparation for a ring.
bnxt_hwrm_ring_free
	This command is used to free a ring and associated resources.

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>