drm/edid: Fix EDID Established Timings I and II

Three of the VESA DMT timings in edid_est_modes[] are slightly off.
1. 640x480@72Hz vsync_end should be 492, not 491.
2. 640x480@60Hz clock should be 25175, not 25200.
3. 1024x768@75Hz clock should be 78750, not 78800.
This patch corrects those timings per the VESA DMT specification, and
thus brings them into line with the identical timings in drm_dmt_modes[].
Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160402100817.B60776E23A@gabe.freedesktop.org

drivers/gpu/drm/drm_edid.c

@@ -522,12 +522,12 @@ static const struct drm_display_mode edid_est_modes[] = {
 		   720, 840, 0, 480, 481, 484, 500, 0,
 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@75Hz */
 	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 31500, 640, 664,
-		   704,  832, 0, 480, 489, 491, 520, 0,
+		   704,  832, 0, 480, 489, 492, 520, 0,
 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@72Hz */
 	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 30240, 640, 704,
 		   768,  864, 0, 480, 483, 486, 525, 0,
 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@67Hz */
-	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 25200, 640, 656,
+	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 25175, 640, 656,
 		   752, 800, 0, 480, 490, 492, 525, 0,
 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@60Hz */
 	{ DRM_MODE("720x400", DRM_MODE_TYPE_DRIVER, 35500, 720, 738,
@@ -539,7 +539,7 @@ static const struct drm_display_mode edid_est_modes[] = {
 	{ DRM_MODE("1280x1024", DRM_MODE_TYPE_DRIVER, 135000, 1280, 1296,
 		   1440, 1688, 0, 1024, 1025, 1028, 1066, 0,
 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 1280x1024@75Hz */
-	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER, 78800, 1024, 1040,
+	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER, 78750, 1024, 1040,
 		   1136, 1312, 0,  768, 769, 772, 800, 0,
 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 1024x768@75Hz */
 	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER, 75000, 1024, 1048,