RDMA/bnxt_re: Specify RDMA component when allocating stats context

Starting FW version 20.6.47, firmware is keeping separate statistics
for L2 and RDMA. However, driver needs to specify RDMA or not when
allocating stat_ctx.

Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>