TI LMU LM363x regulator device tree bindings

LM363x regulator driver supports LM3631 and LM3632.
LM3631 has five regulators and LM3632 supports three regulators.

Required property:
  - compatible: "ti,lm363x-regulator"

Optional properties:
  LM3632 has external enable pins for two LDOs.
  - ti,lcm-en1-gpio: A GPIO specifier for Vpos control pin.
  - ti,lcm-en2-gpio: A GPIO specifier for Vneg control pin.

Child nodes:
  LM3631
  - vboost
  - vcont
  - voref
  - vpos
  - vneg

  LM3632
  - vboost
  - vpos
  - vneg

  Optional properties of a child node:
  Each sub-node should contain the constraints and initialization.
  Please refer to [1].

Examples: Please refer to ti-lmu dt-bindings [2].

[1] ../regulator/regulator.txt
[2] ../mfd/ti-lmu.txt
