Revert "binder: fix max_thread type inconsistency"

This reverts commit e78531e8 which is
commit 42316941 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
Cc: Carlos Llamas <cmllamas@google.com>
Change-Id: Ice729771f03c033b7ffb9a0042c81089e8bb9b10
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>