rockchip: puma: pass platform parameter to TF-A

Puma supports upstream TF-A and is configured to output serial on UART0
instead of the default UART2. Since U-Boot is properly configured to
output on UART0, let's pass the DT to TF-A so there is no need for a
custom TF-A to make the latter output to UART0 too.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>