leverage flashrom fast partial read function to speed up VPD read.

include/lib/vpd.h

Index: include/lib/vpd.h
diff --git a/include/lib/vpd.h b/include/lib/vpd.h
index 1caaf024aae1e4806c11a9d739fd14531d46545e..cd18d613360daf9a69deb1b2ffb6fc3d397cc1c4 100644
--- a/include/lib/vpd.h
+++ b/include/lib/vpd.h
@@ -33,9 +33,13 @@ enum vpd_types {
 /* The default RO VPD location in BIOS image.
  * If VPD partition cannot be found on fmap, buildEpsAndTables() will use
  * this value to count the offset fields of SPD and VPD 2.0.
- *
- * A user can specify -E argument to change the EPS base value. */
-#define GOOGLE_EPS_BASE 0x000000
+ * User can specify -E argument to change the EPS base value.
+ */
+#define GOOGLE_EPS_BASE 0xFFFFFFFF
+/* 0xFFFFFFFF is a special value, which is the value of a blank flash.
+ * It means we don't know the eps->table_address.
+ * This usually happens when we are creating a new VPD partition without
+ * knowing the flash topology (fmap). */
 
 #define GOOGLE_SPD_OFFSET 0x400
 #define GOOGLE_SPD_UUID "75f4926b-9e43-4b32-8979-eb20c0eda76a"