mb/ocp/deltalake: Override SMBIOS type 4 cpu voltage

Override SMBIOS type 4 cpu voltage. For Delta Lake, 1.6V is expected.

Tested=Execute "dmidecode -t 4" to check if cpu voltage is correct.

Signed-off-by: Tim Chu <Tim.Chu@quantatw.com>
Change-Id: I0ecbec8fb3dc79b8c3f3581d6193aade01bcd68e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47562
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jonathan Zhang <jonzhang@fb.com>

src/mainboard/ocp/deltalake/ramstage.c

@@ -59,6 +59,18 @@ const char *smbios_mainboard_location_in_chassis(void)
 	return slot_id_str;
 }
 
+/*
+ * Override SMBIOS type 4 cpu voltage.
+ * BIT7 will set to 1 after value return. If BIT7 is set to 1, the remaining seven
+ * bits of this field are set to contain the processor's current voltage times 10.
+ */
+unsigned int smbios_cpu_get_voltage(void)
+{
+	/* This will return 1.6V which is expected value for Delta Lake
+	   10h = (1.6 * 10) = 16 */
+	return 0x10;
+}
+
 /* System Slot Socket, Stack, Type and Data bus width Information */
 typedef struct {
 	u8 stack;