board: ge: common: vpd: fix name

Commit f692b479 changed the VPD partition name from "vpd" to
"vpd@0". Fix the VPD reader code to use the new name, so that
the VPD code keeps working.

Fixes: f692b479 ("i2c: eeprom: Use reg property instead of offset and size")
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>