drm/xe: Define interrupt vector bits with the interrupt registers

The bit definitions had become a bit orphaned; move them to the same
location as the interrupt registers that they're used with.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231214184659.2249559-16-matthew.d.roper@intel.com


Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>