drm/ast: Fixed 1280x800 Display Issue

The original ast driver cannot display properly if the resolution is 1280x800 and the pixel clock is 83.5MHz.
Here is the update to fix it.

Signed-off-by: Y.C. Chen <yc_chen@aspeedtech.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ast/ast_tables.h b/drivers/gpu/drm/ast/ast_tables.h
index 5f4c2e8..d665dd5 100644
--- a/drivers/gpu/drm/ast/ast_tables.h
+++ b/drivers/gpu/drm/ast/ast_tables.h
@@ -97,7 +97,7 @@ static const struct ast_vbios_dclk_info dclk_table[] = {
 	{0x67, 0x22, 0x00},			/* 0E: VCLK157_5	*/
 	{0x6A, 0x22, 0x00},			/* 0F: VCLK162		*/
 	{0x4d, 0x4c, 0x80},			/* 10: VCLK154		*/
-	{0xa7, 0x78, 0x80},			/* 11: VCLK83.5		*/
+	{0x68, 0x6f, 0x80},			/* 11: VCLK83.5		*/
 	{0x28, 0x49, 0x80},			/* 12: VCLK106.5	*/
 	{0x37, 0x49, 0x80},			/* 13: VCLK146.25	*/
 	{0x1f, 0x45, 0x80},			/* 14: VCLK148.5	*/
@@ -127,7 +127,7 @@ static const struct ast_vbios_dclk_info dclk_table_ast2500[] = {
 	{0x67, 0x22, 0x00},			/* 0E: VCLK157_5	*/
 	{0x6A, 0x22, 0x00},			/* 0F: VCLK162		*/
 	{0x4d, 0x4c, 0x80},			/* 10: VCLK154		*/
-	{0xa7, 0x78, 0x80},			/* 11: VCLK83.5		*/
+	{0x68, 0x6f, 0x80},			/* 11: VCLK83.5		*/
 	{0x28, 0x49, 0x80},			/* 12: VCLK106.5	*/
 	{0x37, 0x49, 0x80},			/* 13: VCLK146.25	*/
 	{0x1f, 0x45, 0x80},			/* 14: VCLK148.5	*/