net/mlx4_core: Use low memory profile on kdump kernel

When running in kdump kernel, reduce number of resources allocated for
the hardware. This will enable the NIC to operate in this low memory
environment at the expense of performance and some features not related
to the basic NIC functionality.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>