openssl: extend check_cwm test timeout

openssl: extend check_cwm test timeout

Fixes [YOCTO 14649]

The default 3s test execution timeout isn't always enough for the check_cwm test
on the autobuilder in case there is a high load on the host machine,
and due to this this case fails sometimes.

This patch doubles the timeout for this testcase to 6 seconds to allow enough
time for execution even if there is high CPU usage by other processes.

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>