Revert "net: inet: Retire port only listening_hash"

This reverts commit 42716542 which is
commit cae3873c upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I442c411d2dd2a01f30d3d9cba5f83510e3fdc2e1
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>