xen: Change xen-acpi-processor dom0 dependency

xen-acpi-processor functions under a PVH dom0 with only a
xen_initial_domain() runtime check.  Change the Kconfig dependency from
PV dom0 to generic dom0 to reflect that.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Tested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Message-ID: <20250331172913.51240-1-jason.andryuk@amd.com>