dt-bindings: clock: add DT binding for the peripheral clocks on Armada 3700

* Peripheral Clock bindings for Marvell Armada 37xx SoCs

Marvell Armada 37xx SoCs provide peripheral clocks which are

used as clock source for the peripheral of the SoC.

There are two different blocks associated to north bridge and south

bridge.

The peripheral clock consumer should specify the desired clock by

having the clock ID in its "clocks" phandle cell.

The following is a list of provided IDs for Armada 370 North bridge clocks:

ID	Clock name	Description

-----------------------------------

0	mmc		MMC controller

1	sata_host	Sata Host

2	sec_at		Security AT

3	sac_dap		Security DAP

4	tsecm		Security Engine

5	setm_tmx	Serial Embedded Trace Module

6	avs		Adaptive Voltage Scaling

7	sqf		SPI

8	pwm		PWM

9	i2c_2		I2C 2

10	i2c_1		I2C 1

11	ddr_phy		DDR PHY

12	ddr_fclk	DDR F clock

13	trace		Trace

14	counter		Counter

15	eip97		EIP 97

16	cpu		CPU

The following is a list of provided IDs for Armada 370 South bridge clocks:

ID	Clock name	Description

-----------------------------------

0	gbe-50		50 MHz parent clock for Gigabit Ethernet

1	gbe-core	parent clock for Gigabit Ethernet core

2	gbe-125		125 MHz parent clock for Gigabit Ethernet

3	gbe1-50		50 MHz clock for Gigabit Ethernet port 1

4	gbe0-50		50 MHz clock for Gigabit Ethernet port 0

5	gbe1-125	125 MHz clock for Gigabit Ethernet port 1

6	gbe0-125	125 MHz clock for Gigabit Ethernet port 0

7	gbe1-core	Gigabit Ethernet core port 1

8	gbe0-core	Gigabit Ethernet core port 0

9	gbe-bm		Gigabit Ethernet Buffer Manager

10	sdio		SDIO

11	usb32-sub2-sys	USB 2 clock

12	usb32-ss-sys	USB 3 clock

Required properties:

- compatible : shall be "marvell,armada-3700-periph-clock-nb" for the

  north bridge block, or

  "marvell,armada-3700-periph-clock-sb" for the south bridge block

- reg : must be the register address of North/South Bridge Clock register

- #clock-cells : from common clock binding; shall be set to 1

- clocks : list of the parent clock phandle in the following order:

  TBG-A P, TBG-B P, TBG-A S, TBG-B S and finally the xtal clock.

Example:

nb_perih_clk: nb-periph-clk@13000{

	compatible = "marvell,armada-3700-periph-clock-nb";

	reg = <0x13000 0x1000>;

	clocks = <&tbg 0>, <&tbg 1>, <&tbg 2>,

	<&tbg 3>, <&xtalclk>;

	#clock-cells = <1>;

};