IB/bnxt_re: Fix frame stack compilation warning

Reduce stack size by dynamically allocating memory instead
of declaring large struct on the stack:

drivers/infiniband/hw/bnxt_re/ib_verbs.c: In function ‘bnxt_re_query_qp’:
drivers/infiniband/hw/bnxt_re/ib_verbs.c:1600:1: warning: the frame size of 1216 bytes is larger than 1024 bytes [-Wframe-larger-than=]
 }
 ^

Cc: Selvin Xavier <selvin.xavier@broadcom.com>
Fixes: 1ac5a404 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reviewed-by: Jonathan Toppins <jtoppins@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>