FT chain is defined as the next chain after tc.

To prepare for next patches that will increase the number of tc
chains available at runtime, use a getter function to get this
value.

The define is still used in static fs_core allocation,
to calculate the number of chains. This static allocation
will be used if the relevant capabilities won't be available
to support dynamic chains.
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>