drm/ast: Fixed 1920x1080 sync. polarity issue

[Bug] Change the vertical synchroous polary of 1920x1080 @60Hz
      from  Negtive to Positive
Signed-off-by: KuoHsiang Chou <kuohsiang_chou@aspeedtech.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105094729.106059-1-kuohsiang_chou@aspeedtech.com

drivers/gpu/drm/ast/ast_tables.h

@@ -295,10 +295,10 @@ static const struct ast_vbios_enhtable res_1600x900[] = {
 
 static const struct ast_vbios_enhtable res_1920x1080[] = {
 	{2200, 1920, 88, 44, 1125, 1080, 4, 5, VCLK148_5,	/* 60Hz */
-	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo |
+	 (SyncPP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo |
 	  AST2500PreCatchCRT), 60, 1, 0x38 },
 	{2200, 1920, 88, 44, 1125, 1080, 4, 5, VCLK148_5,	/* 60Hz */
-	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo |
+	 (SyncPP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo |
 	  AST2500PreCatchCRT), 0xFF, 1, 0x38 },
 };