fvp-linux.rootfs[+rst31]: Set lava_timeout to 25min

Based on sad timeout situation in
https://ci.trustedfirmware.org/job/tf-a-main/530/

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I98d4a8b511aa9fd3e081afb74cf69b5dd8126214
(cherry picked from commit 3fef24e2e8db058813d40b18228f5855f674f3cd)
2 files changed