net/bnxt: refactor the query stats

net/bnxt: refactor the query stats

1) Use hwrm_stat_ctx_query command to query statistics
   Using hwrm_stat_ctx_query command will allow polling
   the statistics from hardware instead of using the current push
   model from the hardware which does a DMA of the stats to the host
   at fixed intervals.

2) Use the rx_mbuf_alloc_fail to track mbuf alloc failures.

3) We were wrongly incrementing hwrm_cmd_seq in bnxt_hwrm_stat_clear
   and bnxt_hwrm_stat_ctx_alloc functions.  This patch fixes that.

Signed-off-by: Stephen Hurd <stephen.hurd@broadcom.com>
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>