Add I2C support in order to subsequently allow disabling the PMIC sleep mode on low supply voltage. Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> Reviewed-by: Simon Glass <sjg@chromium.org> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Tom Warren <twarren@nvidia.com>