cxgb4: Add support to query HW SRQ parameters

This patch adds support to query FW for the HW SRQ table start/end, and
advertise that for ULDs.

Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>