net: mvneta: update clocks property and document additional clock-names

Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/marvell-armada-370-neta.txt

@@ -6,12 +6,17 @@ Required properties:
 - interrupts: interrupt for the device
 - phy: See ethernet.txt file in the same directory.
 - phy-mode: See ethernet.txt file in the same directory
-- clocks: a pointer to the reference clock for this device.
+- clocks: List of clocks for this device. At least one clock is
+  mandatory for the core clock. If several clocks are given, then the
+  clock-names property must be used to identify them.
 
 Optional properties:
 - tx-csum-limit: maximum mtu supported by port that allow TX checksum.
   Value is presented in bytes. If not used, by default 1600B is set for
   "marvell,armada-370-neta" and 9800B for others.
+- clock-names: List of names corresponding to clocks property; shall be
+  "core" for core clock and "bus" for the optional bus clock.
+
 
 Example: