arm64: fix ACPI dependencies

Kconfig reports a warning on x86 builds after the ARM64 dependency
was added.

drivers/acpi/Kconfig:6:error: recursive dependency detected!
drivers/acpi/Kconfig:6:       symbol ACPI depends on EFI

This rephrases the dependency to keep the ARM64 details out of the
shared Kconfig file, so Kconfig no longer gets confused by it.

For consistency, all three architectures that support ACPI now
select ARCH_SUPPORTS_ACPI in exactly the configuration in which
they allow it. We still need the 'default x86', as each one
wants a different default: default-y on x86, default-n on arm64,
and always-y on ia64.

Fixes: 5bcd4408

 ("drivers: acpi: add dependency of EFI for arm64")
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>