drm/radeon: lower the ref * post PLL maximum

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=75241

Signed-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/radeon/radeon_display.c

@@ -862,7 +862,7 @@ static void avivo_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div,
 				 unsigned *fb_div, unsigned *ref_div)
 {
 	/* limit reference * post divider to a maximum */
-	ref_div_max = min(210 / post_div, ref_div_max);
+	ref_div_max = min(128 / post_div, ref_div_max);
 
 	/* get matching reference and feedback divider */
 	*ref_div = min(max(DIV_ROUND_CLOSEST(den, post_div), 1u), ref_div_max);