test_series: fix --reboot_timeout parameter
test_series: fix --reboot_timeout parameter

In the current implementation, the --reboot_timeout parameter is
documented for lisa-wltest-series but cannot be used. This is fixed by
this commit.

Signed-off-by: Quentin Perret <2d02971ddd46effd323a33463a71f9ad92a7835e@arm.com>

ARM-software/lisa,bjackman/lisa,credp/lisa,ARM-software/lisa,ARM-software/lisa,ARM-software/lisa,credp/lisa,bjackman/lisa,credp/lisa,credp/lisa