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

Change-Id: I2fbe6376a1cf98d328464556917638a5679641d2
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/20354
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/include/trace.h

@@ -25,7 +25,7 @@
 
 #else /* !__PRE_RAM__ */
 
-#if CONFIG_TRACE && !defined(__SMM__)
+#if IS_ENABLED(CONFIG_TRACE) && !defined(__SMM__)
 
 void __cyg_profile_func_enter(void *, void *)
 				 __attribute__((no_instrument_function));