ACPI: enable MWAIT for C1 idle

Add MWAIT idle for C1 state instead of halt, on platforms that support
C1 state with MWAIT.

Renames cx->space_id to something more appropriate.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

include/acpi/processor.h

diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 6e253b5..f6d7c50 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -34,6 +34,7 @@
 
 #define ACPI_CSTATE_SYSTEMIO	(0)
 #define ACPI_CSTATE_FFH		(1)
+#define ACPI_CSTATE_HALT	(2)
 
 /* Power Management */
 
@@ -64,7 +65,7 @@
 	u8 valid;
 	u8 type;
 	u32 address;
-	u8 space_id;
+	u8 entry_method;
 	u8 index;
 	u32 latency;
 	u32 latency_ticks;