ibssa _opts.cfg: Cosmetic change to a couple of comment lines

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
core.c: Add support for temporary subnet_up_delay_option

so this can be configured rather than having to rebuild core

NOTE: This option is highly likely to be deprecated in the future!

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