intel/apollolake: Skip ITSS configuration in SMM

In SMM, gpio configuration could be done to avoid leakage. ITSS
configuration is not required when entering sleep. Thus, bail out early
from itss configuration if in SMM.

BUG=chrome-os-partner:56281

Change-Id: I4d8be0513aa202f001f980bb91986b50b8ed2a5b
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/16242
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/soc/intel/apollolake/gpio.c

@@ -72,6 +72,10 @@ static const struct pad_community *gpio_get_community(uint16_t pad)
 static void gpio_configure_itss(const struct pad_config *cfg,
 				uint16_t port, uint16_t pad_cfg_offset)
 {
+	/* No ITSS configuration in SMM. */
+	if (ENV_SMM)
+		return;
+
 	int irq;
 
 	/* Set up ITSS polarity if pad is routed to APIC.