The MT slots devices all follow the same initialization pattern
of creating slots and hinting about buffer size. Let drivers call
an initialization function instead, and make sure it can be called
repeatedly without side effects.
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
In preparation for common code to handle a larger set of MT slots
devices, move the slots handling over to a separate file.
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>