hw/acpi/Kconfig: Rename ACPI_X86_ICH to ACPI_ICH9

hw/acpi/Kconfig: Rename ACPI_X86_ICH to ACPI_ICH9

Although the ICH9 ACPI controller may currently be tied to x86 it
doesn't have to. Furthermore, the source files this configuration switch
manages contain a '9', so this name fits more.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221216130355.41667-2-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>