drm/i915: Sunset igpu legacy mmap support based on GRAPHICS_VER_FULL

The intent of the version check in the mmap ioctl was to maintain
support for existing platforms (i.e., ADL/RPL and earlier), but drop
support on all future igpu platforms.  As we've seen on the dgpu side,
the hardware teams are using a more fine-grained numbering system for IP
version numbers these days, so it's possible the version number
associated with our next igpu could be some form of "12.xx" rather than
13 or higher.  Comparing against the full ver.release number will ensure
the intent of the check is maintained no matter what numbering the
hardware teams settle on.

Fixes: d3f3baa3 ("drm/i915: Reinstate the mmap ioctl for some platforms")
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407161839.1073443-1-matthew.d.roper@intel.com

drivers/gpu/drm/i915/gem/i915_gem_mman.c

@@ -70,7 +70,7 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
 	 * mmap ioctl is disallowed for all discrete platforms,
 	 * and for all platforms with GRAPHICS_VER > 12.
 	 */
-	if (IS_DGFX(i915) || GRAPHICS_VER(i915) > 12)
+	if (IS_DGFX(i915) || GRAPHICS_VER_FULL(i915) > IP_VER(12, 0))
 		return -EOPNOTSUPP;
 
 	if (args->flags & ~(I915_MMAP_WC))