dt-bindings: misc: tegra186-misc: Add missing compatible string

NVIDIA Tegra186 MISC register block

NVIDIA Tegra186 (and later) MISC register block

The MISC register block found on Tegra186 SoCs contains registers that can be

used to identify a given chip and various strapping options.

The MISC register block found on Tegra186 and later SoCs contains registers

that can be used to identify a given chip and various strapping options.

Required properties:

- compatible: Must be:

  - Tegra186: "nvidia,tegra186-misc"

  - Tegra194: "nvidia,tegra194-misc"

- reg: Should contain 2 entries: The first entry gives the physical address

       and length of the register region which contains revision and debug

       features. The second entry specifies the physical address and length