arch/io.h: Add port I/O functions to other architectures

The QEMU Bochs display driver and the QEMU Firmware Configuration
interface code (in the qemu-i440fx mainboard dir) were written for x86.
These devices are available in QEMU VMs of other architectures as well,
so we want to port them to be independent from x86.

The main problem is that the drivers use x86 port I/O functions to
communicate with devices over PCI I/O space. These are currently not
available for ARM* and RISC-V, although it is often still possible to
access PCI I/O ports over MMIO through a translator.

Add implementations of port I/O functions that work with PCI I/O space
on these architectures as well, assuming there is such a translator at a
known address configured at build-time.

Change-Id: If7d9177283e8c692088ba8e30d6dfe52623c8cb9
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80372
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/arch/arm/include/armv4/arch/io.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ARCH_IO_H__
+#define __ARCH_IO_H__
+
+#include <arch-generic/io.h>
+
+#endif

src/arch/arm/include/armv7/arch/io.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ARCH_IO_H__
+#define __ARCH_IO_H__
+
+#include <arch-generic/io.h>
+
+#endif