ARM: imx: vining2000: Convert to ethernet DM

Convert the board to ethernet DM support. Adjust board file accordingly,
as the board_eth_init() contains custom clock configuration required for
this board to work. Furthermore, enable FEC1 clock to make FEC1 work as
well.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Silvio Fricke <silvio.fricke@softing.com>
Cc: Stefano Babic <sbabic@denx.de>