Revert "firmware: vpd: remove platform driver"

This reverts commit 7975bd4c, because
VPD relies on driver core to handle deferrals returned by
coreboot_table_find().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>