can: ti_hecc: Add TI HECC DT binding documentation

Texas Instruments High End CAN Controller (HECC)

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This file provides information, what the device node

for the hecc interface contains.

Required properties:

- compatible: "ti,am3517-hecc"

- reg: addresses and lengths of the register spaces for 'hecc', 'hecc-ram'

       and 'mbx'

- reg-names :"hecc", "hecc-ram", "mbx"

- interrupts: interrupt mapping for the hecc interrupts sources

- clocks: clock phandles (see clock bindings for details)

Optional properties:

- ti,use-hecc1int: if provided configures HECC to produce all interrupts

		   on HECC1INT interrupt line. By default HECC0INT interrupt

		   line will be used.

- xceiver-supply: regulator that powers the CAN transceiver

Example:

For am3517evm board:

	hecc: can@5c050000 {

		compatible = "ti,am3517-hecc";

		reg = <0x5c050000 0x80>,

		      <0x5c053000 0x180>,

		      <0x5c052000 0x200>;

		reg-names = "hecc", "hecc-ram", "mbx";

		interrupts = <24>;

		clocks = <&hecc_ck>;

	};