I82801JX: Add IS_ENABLED around config options

This chipset was just added and had a few places that needed to be
fixed.

Change-Id: Ief048c4876c5a2cb538c9cb4b295aba46a4fff62
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/20684
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/southbridge/intel/i82801jx/lpc.c

@@ -369,7 +369,7 @@ static void enable_clock_gating(void)
 	RCBA32(0x38c0) |= 7;
 }
 
-#if CONFIG_HAVE_SMI_HANDLER
+#if IS_ENABLED(CONFIG_HAVE_SMI_HANDLER)
 static void i82801jx_lock_smm(struct device *dev)
 {
 #if TEST_SMM_FLASH_LOCKDOWN
@@ -464,7 +464,7 @@ static void lpc_init(struct device *dev)
 	/* Interrupt 9 should be level triggered (SCI) */
 	i8259_configure_irq_trigger(9, 1);
 
-#if CONFIG_HAVE_SMI_HANDLER
+#if IS_ENABLED(CONFIG_HAVE_SMI_HANDLER)
 	i82801jx_lock_smm(dev);
 #endif
 }