Allow u-boot-interrupt timeouts to be overridden
Allow u-boot-interrupt timeouts to be overridden

Some boards are slow to get to u-boot, so allow overriding of the
u-boot-interrupt timeout.

Change-Id: Id4f09cd0d52804034ee1342a6d38ba72cdf1499c
Signed-off-by: Sjoerd Simons <1371fd10dd05a897e5b55dc6ae4fbafa1f84c6ec@collabora.co.uk>

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server