rdfremont: Add transport module

Add the transport module and its configuration file to
the rdfremont platform.

Adding this module is required for adding fast channels
to the MHUv3 driver.

The config file for the transport module for the rdfremont
product is a dummy that will be configured once the MHUv3 driver is setup.

Change-Id: I0505a14e4fe600b43be0eaca0b353dd1deb38d11
Signed-off-by: Tomás Agustín González Orlando <tomasagustin.gonzalezorlando@arm.com>