mb/google/volteer: fw_config: Add setting for new sd readers

This patch adds three settings for the new sd readers.
The new assigned values are:
1. RTS5227S: 3
2. L9750: 4
3. SD_OZ711LV2LN: 5

BUG=b:173676531
BRANCH=volteer
TEST=abuild -t google/volteer

Change-Id: I595695f99d3298f146fcdb7c2b942ce007ae9327
Signed-off-by: Zhuohao Lee <zhuohao@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47856
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Caveh Jalali <caveh@chromium.org>

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

@@ -37,6 +37,9 @@ fw_config
 		option SD_ABSENT 0
 		option SD_GL9755S 1
 		option SD_RTS5261 2
+		option SD_RTS5227S 3
+		option SD_L9750 4
+		option SD_OZ711LV2LN 5
 	end
 	field KB_LAYOUT 20 21
 		option KB_LAYOUT_DEFAULT 0