[MLIR][TOSA] Remove ReluN operator from TOSA dialect

[eric-k256]

Summary

ReluN has been removed from the TOSA specification. It can be replaced
in all instances with Clamp(0,N)

Signed-off-by: Eric Kunze <[e-mail]>

[jpienaar]

LG, do you have any pending PRs for downstream users?

[eric-k256]

I didn't find any uses of ReluN downstream, it must have been cleaned up already.

[jpienaar]

SGTM

[jpienaar]

Do you need help in landing?

[eric-k256]

Yes, help landing would be appreciated.

[eric-k256]

Rebased change

[jpienaar]

Sorry missed notification earlier (seems I have some filter configuration error as second one this week), will land once at desk