drm/i915/skl: vfuncs for skl eld and global resource

Set gen 9 function pointers for eld write and global resource.
Implementation remains same as HSW.

v2: Rebase on top of Sonika's untangling of the if/else ladder (Damien)

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Satheeshakrishna M <satheeshakrishna.m@intel.com> (v1)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -12758,6 +12758,10 @@ static void intel_init_display(struct drm_device *dev)
 		dev_priv->display.modeset_global_resources =
 			valleyview_modeset_global_resources;
 		dev_priv->display.write_eld = ironlake_write_eld;
+	} else if (INTEL_INFO(dev)->gen >= 9) {
+		dev_priv->display.write_eld = haswell_write_eld;
+		dev_priv->display.modeset_global_resources =
+			haswell_modeset_global_resources;
 	}
 
 	/* Default just returns -ENODEV to indicate unsupported */