ibcore: Define option to set ack timeout.

Define new option in 'rdma_set_option' to override calculated QP timeout
when requested to provide QP attributes to modify a QP.

At the same time, pack tos_set to be bitfield.

Linux commit:
2c1619edef61a03cb516efaa81750784c3071d10

MFC after: 1 week
Reviewed by: kib
Sponsored by: Mellanox Technologies // NVIDIA Networking