drm/i915: Fork DG1 interrupt handler

The current interrupt handler is getting increasingly complicated and
Xe_HP changes will bring even more complexity.  Let's split off a new
interrupt handler starting with DG1 (i.e., when the master tile
interrupt register was added to the design) and use that as the basis
for the new Xe_HP changes.

Now that we track the hardware IP's release number as well as the
version number, we can also properly define DG1 has version "12.10" and
replace the has_master_unit_irq feature flag with an IP version test.

Bspec: 50875
Cc: Daniele Spurio Ceraolo <daniele.ceraolospurio@intel.com>
Cc: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721223043.834562-5-matthew.d.roper@intel.com