Revert "serial: fsl_lpuart: Fill in rs485_supported"

This reverts commit bd190139 which is
commit a07481f448b635d7cebb92d5940f5bea5c4395a26 upstream.

It is needed as part of a revert in order to preserve the Android abi.
If this needs to be brought back in the future, it can be done so in an
ABI-safe way.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I8de27f1c4e58b3f20b08146eb12f3a5f8b2ab344