ACPI: Add acpi_reset_gnvs_for_wake()

With chipset_power_state filled in romstage CBMEM hooks and
GNVS allocated early in ramstage, GNVS wake source is now
also filled for normal boot path.

Change-Id: I2d44770392d14d2d6e22cc98df9d1751c8717ff3
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50004
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/soc/intel/cannonlake/acpi.c

@@ -175,9 +175,6 @@ void soc_fill_gnvs(struct global_nvs *gnvs)
 	const struct soc_intel_cannonlake_config *config;
 	config = config_of_soc();
 
-	/* Set unknown wake source */
-	gnvs->pm1i = -1;
-
 	/* Enable DPTF based on mainboard configuration */
 	gnvs->dpte = config->dptf_enable;