fvp-linux.rootfs: Extend timeout to 21min

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I8741fc82683906b682a79bf17f13ce38c0e7f18d
(cherry picked from commit 993a094284d2d0ff6c1029cc12497da075bddf8a)
1 file changed