net: ll_temac: Allow use on x86 platforms

With little-endian and 64-bit support in place, the ll_temac driver can
now be used on x86 and x86_64 platforms.

And while at it, enable COMPILE_TEST also.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>