sparc: Move the interrupt types out of isa_traits.hh into interrupts.hh.

sparc: Move the interrupt types out of isa_traits.hh into interrupts.hh.

Those types aren't generic or used outside of SPARC.

Change-Id: I9bb154920a9625f12388c3d295dc933ab51fadde
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18469
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>