platform/x86/amd: pmc: Add helper function to check the cpu id

Add a helper routine to check the underlying cpu id, that can be used
across the PMC driver to remove the duplicate code.
Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230525141929.866385-4-Shyam-sundar.S-k@amd.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/amd/pmc.c

@@ -564,6 +564,18 @@ static void amd_pmc_dbgfs_unregister(struct amd_pmc_dev *dev)
 	debugfs_remove_recursive(dev->dbgfs_dir);
 }
 
+static bool amd_pmc_is_stb_supported(struct amd_pmc_dev *dev)
+{
+	switch (dev->cpu_id) {
+	case AMD_CPU_ID_YC:
+	case AMD_CPU_ID_CB:
+	case AMD_CPU_ID_PS:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
 {
 	dev->dbgfs_dir = debugfs_create_dir("amd_pmc", NULL);
@@ -575,8 +587,7 @@ static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
 			    &amd_pmc_idlemask_fops);
 	/* Enable STB only when the module_param is set */
 	if (enable_stb) {
-		if (dev->cpu_id == AMD_CPU_ID_YC || dev->cpu_id == AMD_CPU_ID_CB ||
-		    dev->cpu_id == AMD_CPU_ID_PS)
+		if (amd_pmc_is_stb_supported(dev))
 			debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev,
 					    &amd_pmc_stb_debugfs_fops_v2);
 		else
@@ -1036,7 +1047,7 @@ static int amd_pmc_probe(struct platform_device *pdev)
 
 	mutex_init(&dev->lock);
 
-	if (enable_stb && (dev->cpu_id == AMD_CPU_ID_YC || dev->cpu_id == AMD_CPU_ID_CB)) {
+	if (enable_stb && amd_pmc_is_stb_supported(dev)) {
 		err = amd_pmc_s2d_init(dev);
 		if (err)
 			goto err_pci_dev_put;