net: Remove all references to CONFIG_ETHADDR and friends

We really don't want boards defining fixed MAC addresses in their config
so we just remove the option to set it in a fixed way. If you must have
a MAC address that was not provisioned, then use the random MAC address
functionality.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

README

@@ -2107,18 +2107,6 @@ CBFS (Coreboot Filesystem) support
 		Some PHY like Intel LXT971A need extra delay after
 		command issued before MII status register can be read
 
-- Ethernet address:
-		CONFIG_ETHADDR
-		CONFIG_ETH1ADDR
-		CONFIG_ETH2ADDR
-		CONFIG_ETH3ADDR
-		CONFIG_ETH4ADDR
-		CONFIG_ETH5ADDR
-
-		Define a default value for Ethernet address to use
-		for the respective Ethernet interface, in case this
-		is not determined automatically.
-
 - IP address:
 		CONFIG_IPADDR
 
@@ -2873,8 +2861,8 @@ CBFS (Coreboot Filesystem) support
 		completely disabled. Anybody can change or delete
 		these parameters.
 
-		Alternatively, if you #define _both_ CONFIG_ETHADDR
-		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
+		Alternatively, if you define _both_ an ethaddr in the
+		default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
 		Ethernet address is installed in the environment,
 		which can be changed exactly ONCE by the user. [The
 		serial# is unaffected by this, i. e. it remains