flashchips: Mark MX25L25635F as tested

As reported by Kasper Revsbech on 2018-10-19.

Change-Id: Icf05288c4e7e34af2e3f4b951457df695078847d
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/29202
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/flashchips.c b/flashchips.c
index 4a66176..8065283 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -8473,7 +8473,7 @@
 		.page_size	= 256,
 		/* OTP: 512B total; enter 0xB1, exit 0xC1 */
 		.feature_bits	= FEATURE_WRSR_WREN | FEATURE_OTP | FEATURE_4BA,
-		.tested		= TEST_UNTESTED,
+		.tested		= TEST_OK_PREW,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
 		.block_erasers	=