[ssa.c, acme.c, distrib/ibssa_opts.cfg]: Limit spacing for rejoin timeout

If rejoin timeout reaches a maximum it becomes constant.
Maximum timeout is
     MAX_REJOIN_TIMEOUT_FACTOR * rejoin_timeout.

Constant MAX_REJOIN_TIMEOUT_FACTOR can be changed from
compiler command line.
For example:
     ./configure CFLAGS="-DMAX_REJOIN_TIMEOUT_FACTOR=2"

Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>