mb/google/zork/var/vilboz: Fix FW_CONFIG_SHIFT_WWAN value

The FW config takes 2 bits for USE_FAN[27,28].
So FW_CONFIG_SHIFT_WWAN value should be 29.

BUG=b:174121847
BRANCH=zork
TEST=build vilboz

Signed-off-by: John Su <john_su@compal.corp-partner.google.com>
Change-Id: Ica6d04f9c48aa0800189283608bf57416ac75cf7
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49236
Reviewed-by: Rob Barnes <robbarnes@google.com>
Reviewed-by: Kangheui Won <khwon@chromium.org>
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>
Reviewed-by: Frank Wu <frank_wu@compal.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/zork/variants/baseboard/helpers.c

@@ -48,7 +48,7 @@ enum {
 	FW_CONFIG_SHIFT_FAN = 27,
 	/* WWAN presence */
 	FW_CONFIG_MASK_WWAN = 0x1,
-	FW_CONFIG_SHIFT_WWAN = 28,
+	FW_CONFIG_SHIFT_WWAN = 29,
 };
 
 static int get_fw_config(uint64_t *val)