intel/sandybridge: Don't hardcode platform type

* Add a function to return CPU platform ID bits
* Add a function to return platform type
** Platform id is 4 on Lenovo T430 (mobile)
** Platform id is 1 on HP8200 (desktop)
* Use introduced method to handle platform specific code
* Use enum for platform type
* Report platform ID

Change-Id: Ifbfc64c8cec98782d6efc987a4d4d5aeab1402ba
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/22530
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 962b830..7cb4069 100644
--- a/src/cpu/intel/model_206ax/model_206ax.h
+++ b/src/cpu/intel/model_206ax/model_206ax.h
@@ -123,5 +123,6 @@
 int cpu_config_tdp_levels(void);
 void smm_relocate(void);
 #endif
+int get_platform_id(void);
 
 #endif