rps: add CONFIG_RPS

RPS currently depends on SMP and SYSFS

Adding a CONFIG_RPS makes sense in case this requirement changes in the
future. This patch saves about 1500 bytes of kernel text in case SMP is
on but SYSFS is off.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/Kconfig b/net/Kconfig
index 041c35e..6851464 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -203,6 +203,11 @@
 source "net/sched/Kconfig"
 source "net/dcb/Kconfig"
 
+config RPS
+	boolean
+	depends on SMP && SYSFS
+	default y
+
 menu "Network testing"
 
 config NET_PKTGEN