drm/i915/dp_mst: Fix symbol clock when calculating the DSC DPT bpp limit

The expected link symbol clock unit when calculating the DSC DPT bpp
limit is kSymbols/sec, aligning with the dotclock's kPixels/sec unit
based on the crtc clock. As opposed to this port_clock is used - which
has a 10 kbits/sec unit - with the resulting symbol clock in 10
kSymbols/sec units (disregarding the rounding error for the 13.5Gbps
rate). Fix the calculation using the expected 10x factor.
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240416221010.376865-3-imre.deak@intel.com

drivers/gpu/drm/i915/display/intel_dp_mst.c

@@ -58,8 +58,7 @@ static int intel_dp_mst_check_constraints(struct drm_i915_private *i915, int bpp
 {
 	if (intel_dp_is_uhbr(crtc_state) && DISPLAY_VER(i915) < 14 && dsc) {
 		int output_bpp = bpp;
-		/* DisplayPort 2 128b/132b, bits per lane is always 32 */
-		int symbol_clock = crtc_state->port_clock / 32;
+		int symbol_clock = intel_dp_link_symbol_clock(crtc_state->port_clock);
 
 		if (output_bpp * adjusted_mode->crtc_clock >=
 		    symbol_clock * 72) {