mlxsw: spectrum_fid: Add an object to keep flood profiles

mlxsw: spectrum_fid: Add an object to keep flood profiles

A flood profile is a mapping from traffic type to an offset at which a
flood vector should be looked up. In mlxsw so far, a flood profile was
somewhat implicitly represented by flood table array. When the CFF flood
mode will be introduced, the flood profile will become more explicit: each
will get a number and the profile ID / traffic-type / offset mapping will
actually need to be initialized in the hardware.

Therefore it is going to be handy to have a structure that keeps all the
components that compose a flood profile. Add this structure, currently with
just the flood table array bits. In the FID families that flood at all,
reference the flood profile instead of just the table array.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/15e113de114d3f41ce3fd2a14a2fa6a1b1d7e8f2.1701183892.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>