cpu/intel/model_206ax: Use haswell cstate_map

Make the code look like on newer platforms. This doesn't change
functionality.

Test: Lenovo X220 still boots and advertises all C-states as
      before.

Change-Id: Ie7076d11720d55a4ac11318cbbdab9f75d08e15e
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78193
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/cpu/intel/model_206ax/model_206ax.h b/src/cpu/intel/model_206ax/model_206ax.h
index b145523..ecbf323 100644
--- a/src/cpu/intel/model_206ax/model_206ax.h
+++ b/src/cpu/intel/model_206ax/model_206ax.h
@@ -109,6 +109,20 @@
 # error "CONFIG_IED_REGION_SIZE is not a power of 2"
 #endif
 
+/*
+ * List of supported C-states for Sandy Bridge/Ivy Bridge.
+ */
+enum {
+	C_STATE_C0		=  0,
+	C_STATE_C1		=  1,
+	C_STATE_C1E		=  2,
+	C_STATE_C3		=  3,
+	C_STATE_C6		=  4,
+	C_STATE_C7		=  5,
+	C_STATE_C7S		=  6,
+	NUM_C_STATES,
+};
+
 /* Lock MSRs */
 void intel_model_206ax_finalize_smm(void);