x86/platform: New Intel Atom SOC power management controller driver

The Power Management Controller (PMC) controls many of the power
management features present in the Atom SoC. This driver provides
a native power off function via PMC PCI IO port.

On some ACPI hardware-reduced platforms(e.g. ASUS-T100), ACPI sleep
registers are not valid so that (*pm_power_off)() is not hooked by
acpi_power_off(). The power off function in this driver is installed
only when pm_power_off is NULL.

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Link: http://lkml.kernel.org/r/53B0FEEA.3010805@linux.intel.com
Signed-off-by: Lejun Zhu <lejun.zhu@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a8f749e..6295a21 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2403,6 +2403,10 @@
 	default m
 	depends on PCI
 
+config PMC_ATOM
+	def_bool y
+        depends on PCI
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"