Marvell: Armada7k8k/OcteonTx: Switch SPCR UART subtype to 0x1

DBG2 ACPI table description [1] specifies three subtypes
related to 16550 UART:
0x0 - 16550 compatible
0x1 - 16550 subset
0x12 - 16550 compatible with parameters defined in
       Generic Address Structure (GAS)

It turned out however, that the Windows OS treats 0x0 subtype as
legacy x86 UART with 8-bit access. ARM SoCs can use types 0x1 (16550 with
fixed mmio32 access) or 0x12 (16550 with fully respected GAS contents).

Switch Marvell SoCs ACPI UART subtype to 0x1 - thanks to that the
same firmware can run properly with UART output in Windows 10, Linux
and ESXI hypervisor.

[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/acpi-debug-port-table



Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-By: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
Reviewed-by: Sunny Wang <sunny.wang@arm.com>