drm/i915: Introduce intel_csc_matrix struct

Introduce a structure that can hold our CSC matrices. In there
we shall have the preoffsets, postoffsets, and coefficients,
all in platform specific format (at least for now).

We shall start by converting the ilk+ code to make use of
the new structure. chv will come later.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230329135002.3096-3-ville.syrjala@linux.intel.comReviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -980,6 +980,12 @@ struct intel_link_m_n {
 	u32 link_n;
 };
 
+struct intel_csc_matrix {
+	u16 coeff[9];
+	u16 preoff[3];
+	u16 postoff[3];
+};
+
 struct intel_crtc_state {
 	/*
 	 * uapi (drm) state. This is the software state shown to userspace.