Change the status of the SST49LF020A to TEST_OK_PREW

I tested it on the Wyse Winterm S50 see attached test results.

Corresponding to flashrom svn r730.

Signed-off-by: Nils Jacobs <njacobs8@hetnet.nl>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
diff --git a/flashchips.c b/flashchips.c
index 0983f1d..83f6e96 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -2244,7 +2244,7 @@
 		.model_id	= SST_49LF020A,
 		.total_size	= 256,
 		.page_size	= 4 * 1024,
-		.tested		= TEST_UNTESTED,
+		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 1,			/* 150 ns */ 
 		.erase		= erase_49lf040,