Fix SyncMOS S29C51004T, which has 512 uniform 1k sectors

Corresponding to flashrom svn r873.
Signed-off-by: Sean Nelson <audiohacked@gmail.com>
Acked-by: Sean Nelson <audiohacked@gmail.com>

flashchips.c

@@ -5043,7 +5043,7 @@ struct flashchip flashchips[] = {
 		.block_erasers	=
 		{
 			{
-				.eraseblocks = { {1 * 1024, 496} },
+				.eraseblocks = { {1 * 1024, 512} },
 				.block_erase = erase_sector_jedec,
 			}, {
 				.eraseblocks = { {512 * 1024, 1} },