drivers/net: Remove "select SRCU"

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it.  Therefore, remove the "select SRCU"
Kconfig statements.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: John Ogness <john.ogness@linutronix.de>

drivers/net/Kconfig

@@ -334,7 +334,6 @@ config NETCONSOLE_DYNAMIC
 
 config NETPOLL
 	def_bool NETCONSOLE
-	select SRCU
 
 config NET_POLL_CONTROLLER
 	def_bool NETPOLL