net: imx: Add multi-FEC support for imx_get_mac_from_fuse

Add multi-FEC support for imx_get_mac_from_fuse by passing dev_id as a parameter.

This feature is important on mx28 SoC for example that has two FEC ports.

Cc: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>