RDMA/core: Increase total number of RDMA ports across all devices

IDA adds overhead to store IDs bitmap with maximal value of IDA
can be upto 2099202 (IDA_MAX = 0x80000000U / IDA_BITMAP_BITS - 1).

However, there is no need to add such enormous number of devices
and it is enough for now to limit it to be 8192.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>