mfd_add_devices enables parsing device tree nodes without compatibles
for regulators and gpio modules. Replace of_platform_populate with
mfd_add_devices. mfd_cell currently is populated with regulators,
gpio and powerbutton.
Signed-off-by: NKeerthy <j-keerthy@ti.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>