Modbus is failing to turn on RX when using serial ASYNC mode. This
causes modbus to never receive inbound requests, leaving it inoperable.
Additionally, modbus also enables RX when in client mode, leading to
issues when running as a client. These have been fixed by enabling rx
only when serial init is successful and modbus is in server mode during
initialisation.
Signed-off-by: Ryan Wiebe <ryan.wiebe@analog.com>
8135c56cf6