rockchip: px30-board-tpl: Sync ifdef guards with full TPL

rockchip: px30-board-tpl: Sync ifdef guards with full TPL

Display TPL init information message only when TPL_BANNER_PRINT
configuration entry is set. This allows to disable information
message in case logs on UART are unwanted.
Update parent ifdef condition to check also CONFIG_TPL_SERIAL
to match logic of the non-PX30 TPL implementation.

Signed-off-by: Lukasz Czechowski <lukasz.czechowski@thaumatec.com>
Reviewed-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>