ec/google/chromeec: Add _PRW property to CREC device

This change adds _PRW property to CREC device that allows Linux kernel
to identify CREC as a wakeup source.

BUG=b:69118395
TEST=Verified following steps:
1. Under sys devices for CREC: "echo enabled > wakeup"
2. Lid close/Lid open -- Verified that wakeup_count increases
3. Mode change -- Verified that wakeup_count increases

Change-Id: Ib0a687e171c7e5c81325b39f47c9a2462553fe3e
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/23399
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
diff --git a/src/ec/google/chromeec/acpi/cros_ec.asl b/src/ec/google/chromeec/acpi/cros_ec.asl
index 7f3afea..b246fe3 100644
--- a/src/ec/google/chromeec/acpi/cros_ec.asl
+++ b/src/ec/google/chromeec/acpi/cros_ec.asl
@@ -18,6 +18,9 @@
 	Name (_HID, "GOOG0004")
 	Name (_UID, 1)
 	Name (_DDN, "EC Command Device")
+#ifdef EC_ENABLE_WAKE_PIN
+	Name (_PRW, Package () { EC_ENABLE_WAKE_PIN, 0x5 })
+#endif
 
 #ifdef EC_ENABLE_MKBP_DEVICE
 	Device (CKSC)