intel/fsp_baytrail: Don't clear gnvs in acpi_init_gnvs()

That wipes out all previously stored settings and breaks running devices
in ACPI mode.
This more closely matches what is done in intel/baytrail.

Change-Id: Ie993c9f9e1eceb73d016d2df72770a27abb26ec1
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
Reviewed-on: https://review.coreboot.org/14040
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/intel/fsp_baytrail/acpi.c

@@ -85,9 +85,6 @@ static acpi_cstate_t cstate_map[] = {
 
 void acpi_init_gnvs(global_nvs_t *gnvs)
 {
-	/* Clear gnvs area so uninitialized portions are defined */
-	memset(gnvs, 0, sizeof(*gnvs));
-
 	/* CPU core count */
 	gnvs->pcnt = dev_count_cpu();