smsc95xx: mark link down on startup and let PHY interrupt deal with carrier changes

Without this patch sysfs reports the cable as present

flag@flag-desktop:~$ cat /sys/class/net/eth0/carrier
1

while it's not:

flag@flag-desktop:~$ sudo mii-tool eth0
eth0: no link

Tested on my Beagle XM.

v2: added mantainer to the list of recipient

Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: David S. Miller <davem@davemloft.net>