dt-bindings: net: add fsl,erratum-a011043

Add an entry for erratum A011043: the MDIO_CFG[MDIO_RD_ER]
bit may be falsely set when reading internal PCS registers.
MDIO reads to internal PCS registers may result in having
the MDIO_CFG[MDIO_RD_ER] bit set, even when there is no
error and read data (MDIO_DATA[MDIO_DATA]) is correct.
Software may get false read error when reading internal
PCS registers through MDIO. As a workaround, all internal
MDIO accesses should ignore the MDIO_CFG[MDIO_RD_ER] bit.

Signed-off-by: Madalin Bucur <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/devicetree/bindings/net/fsl-fman.txt

···
 		The settings and programming routines for internal/external
 		MDIO are different. Must be included for internal MDIO.
 
+- fsl,erratum-a011043
+		Usage: optional
+		Value type: <boolean>
+		Definition: Indicates the presence of the A011043 erratum
+		describing that the MDIO_CFG[MDIO_RD_ER] bit may be falsely
+		set when reading internal PCS registers. MDIO reads to
+		internal PCS registers may result in having the
+		MDIO_CFG[MDIO_RD_ER] bit set, even when there is no error and
+		read data (MDIO_DATA[MDIO_DATA]) is correct.
+		Software may get false read error when reading internal
+		PCS registers through MDIO. As a workaround, all internal
+		MDIO accesses should ignore the MDIO_CFG[MDIO_RD_ER] bit.
+
 For internal PHY device on internal mdio bus, a PHY node should be created.
 See the definition of the PHY node in booting-without-of.txt for an
 example of how to define a PHY (Internal PHY has no interrupt line).