New Ethernet initialization

Hello,

By any measure, net/eth.c is messy and only gets worse as each new Ethernet controller gets added. This patch moves initialization to board code, providing the following benefits:

1. Board developers have more control over the ordering of Ethernet interfaces on a board, and can easily instantiate several different interfaces. This will make a PHY library easier to implement.
2. Ethernet controllers are decoupled from the net library.
3. /net/eth.c will become much smaller and easier to read.

I've initially implemented only on TSEC, because I have a couple of different boards with this controller (MPC8349EMDS and MPC8555CDS) and am able to test it. Note that in this patch the TSEC driver itself isn't touched - only where it's initialized.

If feedback is positive, I'll port all other in-tree controllers and boards and will put in a branch of the net tree. Hopefully volunteers will line up to sanity test.

Please have a look and let me know your thoughts.

regards,
Ben

I appreciate the approach.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Always try to do things in chronological order; it's  less  confusing
that way.