mfd: rn5t618: Document device tree bindings

This adds the device tree bindings documentation for Ricoh RN5T618.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
1 file changed