xen/acpi-processor: Do not depend on CPU frequency scaling drivers.

With patch "xen/cpufreq: Disable the cpu frequency scaling drivers
from loading." we do not have to worry about said drivers loading
themselves before the xen-acpi-processor driver. Hence we can remove
the default selection (=y if CPU frequency drivers were built-in, or
=m if CPU frequency drivers were built as modules), and just
select =m for the default case.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/Kconfig

@@ -181,8 +181,7 @@ config XEN_PRIVCMD
 config XEN_ACPI_PROCESSOR
 	tristate "Xen ACPI processor"
 	depends on XEN && X86 && ACPI_PROCESSOR
-	default y if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)
-	default m if (X86_ACPI_CPUFREQ = m || X86_POWERNOW_K8 = m)
+	default m
 	help
           This ACPI processor uploads Power Management information to the Xen hypervisor.