sgi575/run_model: route uart logs via secure/non-secure uart

Use secure and non-secure uarts in CSS instead of the uarts in SOC.
TF-A boot, runtime and Standalone MM logs would be routed via
css.pl011_uart1_ap (secure port). UEFI and OS logs would be routed via
css.pl011_uart_ap (non-secure port)

Additionally, as TF-A and MM logs would be routed via the same UART
port, remove unused model parameters that are used for configuring uart
port for capturing Standalone MM logs.

Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
Change-Id: I9495b3d3a1852b87ac1c832ead5b64d917e828c6