AMD Bettong: Enable S4 feature for Windows 7

PMIOxEE is for setting USB3 power rail. Set it to S0, otherwise
going into hibernation can not be wake up.

Change-Id: I692497bad24d745738d670897e725a568c1db114
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/11373
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins)

src/mainboard/amd/bettong/romstage.c

@@ -15,6 +15,7 @@
 
 #include <console/console.h>
 #include <arch/acpi.h>
+#include <arch/io.h>
 #include <arch/stages.h>
 #include <cpu/x86/lapic.h>
 #include <cpu/x86/bist.h>
@@ -78,6 +79,11 @@ void cache_as_ram_main(unsigned long bist, unsigned long cpu_init_detectedx)
 		prepare_for_resume();
 	}
 
+	if (s3resume || acpi_is_wakeup_s4()) {
+		outb(0xEE, PM_INDEX);
+		outb(0x8, PM_DATA);
+	}
+
 	post_code(0x50);
 	copy_and_run();