Documentation: bindings: move the Berlin reset documentation

The Berlin reset documentation was part of the Marvell Berlin SoC
documentation because the Berlin reset configuration was inside the chip
controller. With the recent rework of the chip and system controller
handling (now an MFD driver registers all sub-devices of the two soc and
system controller nodes and each device has its own sub-node), the
documentation of the Berlin reset driver can be moved to the generic
reset documentation directory.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

Documentation/devicetree/bindings/arm/marvell,berlin.txt

@@ -124,21 +124,11 @@ Required subnode-properties:
 - groups: a list of strings describing the group names.
 - function: a string describing the function used to mux the groups.
 
-* Reset controller binding
-
-A reset controller is part of the chip control registers set. The chip control
-node also provides the reset. The register set is not at the same offset between
-Berlin SoCs.
-
-Required property:
-- #reset-cells: must be set to 2
-
 Example:
 
 chip: chip-control@ea0000 {
 	compatible = "marvell,berlin2-chip-ctrl", "simple-mfd", "syscon";
 	#clock-cells = <1>;
-	#reset-cells = <2>;
 	reg = <0xea0000 0x400>;
 	clocks = <&refclk>, <&externaldev 0>;
 	clock-names = "refclk", "video_ext0";

Documentation/devicetree/bindings/reset/berlin,reset.txt

@@ -0,0 +1,23 @@
+Marvell Berlin reset controller
+===============================
+
+Please also refer to reset.txt in this directory for common reset
+controller binding usage.
+
+The reset controller node must be a sub-node of the chip controller
+node on Berlin SoCs.
+
+Required properties:
+- compatible: should be "marvell,berlin2-reset"
+- #reset-cells: must be set to 2
+
+Example:
+
+chip_rst: reset {
+	compatible = "marvell,berlin2-reset";
+	#reset-cells = <2>;
+};
+
+&usb_phy0 {
+	resets = <&chip_rst 0x104 12>;
+};