drm/xe/irq: Drop remaining "gen11_" prefix from IRQ functions

The remaining "gen11_*" IRQ functions are common to all platforms
supported by the Xe driver.  Drop the unnecessary prefix.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20230401002106.588656-7-matthew.d.roper@intel.com


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