tc1100-wmi: fix build warning when CONFIG_PM not enabled

Conditionally declare suspend_data on CONFIG_PM to avoid
the following warning when CONFIG_OM is not enabled:

drivers/platform/x86/tc1100-wmi.c:55:27: warning:
  'suspend_data' defined but not used [-Wunused-variable]
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

drivers/platform/x86/tc1100-wmi.c

@@ -52,7 +52,9 @@ struct tc1100_data {
 	u32 jogdial;
 };
 
+#ifdef CONFIG_PM
 static struct tc1100_data suspend_data;
+#endif
 
 /* --------------------------------------------------------------------------
 				Device Management