bnxt_en: remove redundant debug register dma mem allocation

hwrm_dbg_resp_addr and hwrm_dbg_resp_dma_addr are never used
and can be removed.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>