arm: vybrid: Drop enabling GPIO, SPI and UART in legacy mode

Remove the legacy way of enabling GPIO, SPI and UART on Vybrid
based boards since these driver's now only supports DT mode.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>