drivers: thermal: processor_thermal_device: Fix build warning

As a system sleep callback, proc_thermal_resume() should be defined only
if CONFIG_PM_SLEEP is defined.

This fixes a build warning when CONFIG_PM_SLEEP is not set,
drivers/thermal/intel/int340x_thermal/processor_thermal_device.c:446:12: error: 'proc_thermal_resume' defined but not used [-Werror=unused-function]
 static int proc_thermal_resume(struct device *dev)

Fixes: aaba9791 ("drivers: thermal: processor_thermal: Read PPCC on resume")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/intel/int340x_thermal/processor_thermal_device.c

@@ -443,6 +443,7 @@ static void  proc_thermal_pci_remove(struct pci_dev *pdev)
 	pci_disable_device(pdev);
 }
 
+#ifdef CONFIG_PM_SLEEP
 static int proc_thermal_resume(struct device *dev)
 {
 	struct proc_thermal_device *proc_dev;
@@ -452,6 +453,9 @@ static int proc_thermal_resume(struct device *dev)
 
 	return 0;
 }
+#else
+#define proc_thermal_resume NULL
+#endif
 
 static SIMPLE_DEV_PM_OPS(proc_thermal_pm, NULL, proc_thermal_resume);