[U-Boot] change fdt_fixup_ethernet to use env instead of bd_t

[Kumar Gala]

Does anyone see any issue with moving to using the environment instead of
the bd_t to get the mac address for a given ethernet controller.  This has
the benefit of having this bit of code scales easier w/the # of
controllers.

Right now I've set the max to 10, but we can easily make it configurable.

- k

void fdt_fixup_ethernet(void *fdt)
{
        int i, j;
        int node;
        const char *path;

        node = fdt_path_offset(fdt, "/aliases");
        if (node >= 0) {
                char enet[12], mac[10], *tmp, *end;
                unsigned char mac_addr[6];

                for (i = 0; i < 10; i++) {
                        sprintf(enet, "ethernet%d", i);
                        sprintf(mac, "eth%daddr",i);

                        sprintf(mac, i ? "eth%daddr" : "ethaddr", i);
                        tmp = getenv(mac);
                        path = fdt_getprop(fdt, node, enet, NULL);

                        if (!path) {
                                continue;
                        }
                        if (!tmp) {
                                continue;
                        }

                        for (j = 0; j < 6; j++) {
                                mac_addr[j] = tmp ? simple_strtoul(tmp, &end, 16) : 0;
                                if (tmp)
                                        tmp = (*end) ? end+1 : end;
                        }

                        do_fixup_by_path(fdt, path, "mac-address",
                                        &mac_addr, 6, 0);
                        do_fixup_by_path(fdt, path, "local-mac-address",
                                        &mac_addr, 6, 1);
                }
        }
}