sandbox: Enable MC34708 PMIC support

This MC34708 PMIC is somewhat special - it used single transfers (R/W) with
3 bytes size - up till now U-Boot's PMICs only used 1 byte.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
3 files changed