net/bnxt: modify ring index logic

net/bnxt: modify ring index logic

Change the ring logic so that the index increments
unbounded and mask it only when needed.

Modify the existing macros so that the index is not masked.
Add a new macro RING_IDX() to mask it only when needed.

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Acked-by: Lance Richardson <lance.richardson@broadcom.com>