drm/i915/skl: Definition of SKL WM param structs for pipe/plane

This patch defines the structures needed for computation of
watermarks of pipes and planes for SKL.

v2: Incorporated Damien's review comments and removed unused fields
    in structs for future features like rotation, drrs and scaling.
    The skl_wm_values struct is now made more generic across planes
    and cursor planes for all pipes.

v3: implemented the plane/cursor split.

v4: Change the wm union back to a structure (Ville, Daniel)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Pradeep Bhat <pradeep.bhat@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index c8ddde6..446be27 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -412,6 +412,12 @@
 	struct work_struct work;
 };
 
+struct skl_pipe_wm {
+	struct skl_wm_level wm[8];
+	struct skl_wm_level trans_wm;
+	uint32_t linetime;
+};
+
 struct intel_crtc {
 	struct drm_crtc base;
 	enum pipe pipe;
@@ -459,6 +465,8 @@
 	struct {
 		/* watermarks currently being used  */
 		struct intel_pipe_wm active;
+		/* SKL wm values currently in use */
+		struct skl_pipe_wm skl_active;
 	} wm;
 
 	int scanline_offset;