[PATCH v3] powerpc: add of_get_mac_address() and update fsl_soc.c to use it

[Paul Mackerras]

Timur Tabi writes:

> Add function of_get_mac_address(), which obtains the best MAC address to use
> from the device tree by checking various properties in order.  The order is:
> 'mac-address', then 'local-mac-address', then 'address'.  It skips properties 
> that contain invalid MAC addresses, which were probably not initialized
> by U-Boot.

Looks OK except that of_get_mac_address should go in prom_parse.c, not
prom.c.

Paul.