vbox: add HAS_IOPORT dependency

The vboxguest driver depends on port I/O for debug output:

include/asm-generic/io.h:626:15: error: call to '_outl' declared with attribute error: outl() requires CONFIG_HAS_IOPORT
626 | #define _outl _outl
include/asm-generic/io.h:663:14: note: in expansion of macro '_outl'
663 | #define outl _outl
| ^~~~~
drivers/virt/vboxguest/vboxguest_utils.c:102:9: note: in expansion of macro 'outl'
102 | outl(phys_req, gdev->io_port + VMMDEV_PORT_OFF_REQUEST);
| ^~~~

Most arm64 platforms don't actually support port I/O, though it is
currently enabled unconditionally. Refine the vbox dependency to allow
turning HAS_IOPORT off in the future when building for platforms without
port I/O and allow compile-testing on all architectures.

Fixes: 5cf8f938bf5c ("vbox: Enable VBOXGUEST and VBOXSF_FS on ARM64")
Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Hans de Goede <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/virt/vboxguest/Kconfig

···
 # SPDX-License-Identifier: GPL-2.0-only
 config VBOXGUEST
 	tristate "Virtual Box Guest integration support"
-	depends on (ARM64 || X86) && PCI && INPUT
+	depends on (ARM64 || X86 || COMPILE_TEST) && PCI && INPUT
+	depends on HAS_IOPORT
 	help
 	  This is a driver for the Virtual Box Guest PCI device used in
 	  Virtual Box virtual machines. Enabling this driver will add