flashchips.c: Mark GD25Q40(B) as tested

As mentioned by Wolf Dieter Brandt in his mail from 07.Feb.22.

Change-Id: Idec3d82efbdf095c3d57bfe5f0fd487007b554cb
Signed-off-by: Simon Buhrow <simon.buhrow@posteo.de>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/62712
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/70978
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/flashchips.c b/flashchips.c
index bf05e96..ec63cf7 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -6821,7 +6821,7 @@
 		.total_size	= 512,
 		.page_size	= 256,
 		.feature_bits	= FEATURE_WRSR_WREN,
-		.tested		= TEST_UNTESTED,
+		.tested		= TEST_OK_PREW,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
 		.block_erasers	=