dt-bindings: net: stmmac: add phys config properties

Add properties to support all Phy config
 PHY_MODE	(MII,GMII, RMII, RGMII) and in normal, PHY wo crystal (25Mhz),
 PHY wo crystal (50Mhz), No 125Mhz from PHY config.
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/stm32-dwmac.txt

@@ -24,9 +24,9 @@ Required properties:
 	       encompases the glue register, and the offset of the control register.
 
 Optional properties:
-- clock-names:     For MPU family "mac-clk-ck" for PHY without quartz
-- st,int-phyclk (boolean) :  valid only where PHY do not have quartz and need to be clock
-	           by RCC
+- clock-names:     For MPU family "eth-ck" for PHY without quartz
+- st,eth-clk-sel (boolean) : set this property in RGMII PHY when you want to select RCC clock instead of ETH_CLK125.
+- st,eth-ref-clk-sel (boolean) :  set this property in RMII mode when you have PHY without crystal 50MHz and want to select RCC clock instead of ETH_REF_CLK.
 
 Example: