drm/i915/tgl: Gen12 render context size

Re-use Gen11 context size for now.

[ Lucas: this is a temporary enabling patch that needs to be confirmed:
         we need to check BSpec 46255 and recompute ]
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190817093902.2171-27-lucas.demarchi@intel.com

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -164,6 +164,7 @@ u32 intel_engine_context_size(struct drm_i915_private *dev_priv, u8 class)
 		default:
 			MISSING_CASE(INTEL_GEN(dev_priv));
 			return DEFAULT_LR_CONTEXT_RENDER_SIZE;
+		case 12:
 		case 11:
 			return GEN11_LR_CONTEXT_RENDER_SIZE;
 		case 10: