net: tcp: Extend TCP receive queue timeout

After several fixes of the re-ordering logic in TCP, the receive queue
works as intended and cleans itself up properly. Previously the default
timeout was 100 ms, which pretty much disables it for real applications.

Increase the timeout to 2 seconds to actually enable it for in practice.
This should help pass much more of the Maxwell Pro tests.

This is the first step before removing the timeout completely.

Signed-off-by: Sjors Hettinga <s.a.hettinga@gmail.com>