qcs405: Add PRESERVE flag for RO_VPD

Add PRESERVE flag to preserve the VPD data.

Change-Id: I78ab4de31030465345c5ae58813bfed5e27494fb
Signed-off-by: Nitheesh Sekar <nsekar@codeaurora.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33020
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/mistral/chromeos.fmd

@@ -22,7 +22,7 @@ FLASH@0x0 8M {
 			GBB 0x2f00
 			RO_FRID 0x100
 		}
-		RO_VPD 128K
+		RO_VPD(PRESERVE) 128K
 		RO_DDR_TRAINING(PRESERVE) 8K
 	}