autotest: extend flash firmware timeout, FIRMWARE_PROGRAM_TIMEOUT_SEC

This patch extends the firmware program timeout to 1800 seconds.
As the data size in AP image grows, the actual time taken in
flashrom, especially with ccd, increases as well. For example, Zork AP
image has 48% more data compared to Grunt AP image.

BUG=b:170333462
TEST=none

Change-Id: Ifb0c3814aedf69feb162080223b2bfceda419cc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2480612
Tested-by: Namyoon Woo <namyoon@chromium.org>
Auto-Submit: Namyoon Woo <namyoon@chromium.org>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>
Commit-Queue: Mary Ruthven <mruthven@chromium.org>
diff --git a/server/cros/servo/firmware_programmer.py b/server/cros/servo/firmware_programmer.py
index b71032e..c32dc21 100644
--- a/server/cros/servo/firmware_programmer.py
+++ b/server/cros/servo/firmware_programmer.py
@@ -24,7 +24,7 @@
 
 
 # Number of seconds for program EC/BIOS to time out.
-FIRMWARE_PROGRAM_TIMEOUT_SEC = 900
+FIRMWARE_PROGRAM_TIMEOUT_SEC = 1800
 
 class ProgrammerError(Exception):
     """Local exception class wrapper."""