mb/google/volteer: Add fw_config entries for boot device

Add the fw_config entries for the newly added boot device fields.
These are added as separate fields since a board may have more
than one selected.

BUG=b:173129299
TEST=abuild google/volteer

Change-Id: I2af9ffcf0b90d4f4b7f2f31613ee110d8f350454
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48160
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/mainboard/google/volteer/variants/baseboard/devicetree.cb

@@ -46,6 +46,18 @@ fw_config
 		option KB_LAYOUT_DEFAULT 0
 		option KB_LAYOUT_1 1
 	end
+	field BOOT_DEVICE_EMMC 22
+		option BOOT_EMMC_DISABLED 0
+		option BOOT_EMMC_ENABLED 1
+	end
+	field BOOT_DEVICE_NVME 23
+		option BOOT_NVME_DISABLED 0
+		option BOOT_NVME_ENABLED 1
+	end
+	field BOOT_DEVICE_SATA 24
+		option BOOT_SATA_DISABLED 0
+		option BOOT_SATA_ENABLED 1
+	end
 end
 
 chip soc/intel/tigerlake