Create new TTIROpInterface methods

[nsmithtt]

Update include/ttmlir/Dialect/TTIR/IR/TTIROpsInterfaces.td, update op interface def TTIROpInterface to include 2 new op interface methods:

• bool supportsCPUExecution();: Denotes that this op can use the CPU for execution
• bool supportsOnlyCPUExecution();: Denotes that this op must use the CPU for execution

Both should default return false, individual ops will have to override them to return true. If they return true, it can be asserted that there exists a dialect conversion for this TTIR op into a CPU compatible dialect.

[nsmithtt]

@sdjordjevicTT, in the doc we said these should be traits, do you have any preference if they have dedicated traits vs just being boolean queries on TTIROpInterface?

[sdjordjevicTT]

@sdjordjevicTT, in the doc we said these should be traits, do you have any preference if they have dedicated traits vs just being boolean queries on TTIROpInterface?

Sound good and makes sense as each op can override it through interface methods, hence we are getting the same behaviour.

[nsmithtt]

The only thing I was thinking is that presumably we will have a dialect conversion that does TTIRToTOSA or something, then there is just kind of an implicit contract that if supportsCPUExecution returns true there must be a conversion path for it. That said, it might not be a big deal, and there might be cases where we want to selectively disable supportsCPUExecution despite there being a tosa conversion for it. I'm probably overthinking it 😅