netdev: Depend on INET before selecting INET_LRO

Since 'select' ignores dependencies, drivers that select INET_LRO must
depend on INET.  This fixes the broken configuration reported in
<http://article.gmane.org/gmane.linux.kernel/825646

>.

Reported-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>