mb/google/fizz: allow 8 bit sku ids

Change-Id: I663678a4c572fe80298f7388870d5cd403122b98
Signed-off-by: Jeff Chase <jnchase@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39109
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Shelley Chen <shchen@google.com>

src/mainboard/google/fizz/mainboard.c

@@ -184,7 +184,7 @@ static uint8_t board_oem_id(void)
 
 const char *smbios_system_sku(void)
 {
-	static char sku_str[5]; /* sku{0..7} */
+	static char sku_str[7]; /* sku{0..255} */
 
 	snprintf(sku_str, sizeof(sku_str), "sku%d", board_oem_id());