tools/power/x86/intel-speed-select: Introduce api_version helper

In some cases, the output format may be different with different
api_version because of different capabilities or for backward
capabilities reason.

Introduce api_version() to get the api_version of the platform running.

No functional changes are expected.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[srinivas.pandruvada@linux.intel.com: changelog edits]
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

tools/power/x86/intel-speed-select/isst-config.c

@@ -166,6 +166,11 @@ static int update_cpu_model(void)
 	return 0;
 }
 
+int api_version(void)
+{
+        return isst_platform_info.api_version;
+}
+
 /* Open a file, and exit on failure */
 static FILE *fopen_or_exit(const char *path, const char *mode)
 {

tools/power/x86/intel-speed-select/isst.h

@@ -213,6 +213,7 @@ extern int is_cpu_in_power_domain(int cpu, struct isst_id *id);
 extern int get_topo_max_cpus(void);
 extern int get_cpu_count(struct isst_id *id);
 extern int get_max_punit_core_id(struct isst_id *id);
+extern int api_version(void);
 
 /* Common interfaces */
 FILE *get_output_file(void);