src/ec: add IS_ENABLED() around Kconfig symbol references

Change-Id: Ic2cdfa08cdae9f698eb2f8fa4c4ae061f1a7d903
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/20340
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

src/ec/google/chromeec/ec.c

@@ -466,7 +466,7 @@ u32 google_chromeec_get_wake_mask(void)
 
 void google_chromeec_log_events(u32 mask)
 {
-#if CONFIG_ELOG
+#if IS_ENABLED(CONFIG_ELOG)
 	u8 event;
 	u32 wake_mask;