configs: Remove CONFIG_NET_MULTI from board files

configs: Remove CONFIG_NET_MULTI from board files

CONFIG_NET_MULTI is not used anymore, so remove it from board files.

Cc: Marek Vasut <[email protected]>
Cc: Stefano Babic <[email protected]>
Cc: Kumar Gala <[email protected]>
Cc: Sandeep Paulraj <[email protected]>
Signed-off-by: Fabio Estevam <[email protected]>
Acked-by: Tom Rini <[email protected]>
Acked-by: Mike Frysinger <[email protected]>
Acked-by: Marek Vasut <[email protected]>
Acked-by: Heiko Schocher <[email protected]>
Acked-by: Kumar Gala <[email protected]>
Acked-by: Stefano Babic <[email protected]>
Tested-by: Marek Vasut <[email protected]>
Tested-by: Heiko Schocher <[email protected]>