doc: move seg6_flowlabel to seg6-sysctl.rst

Let's have all seg6 sysctl at the same place.

Fixes: a6dc6670cd7e ("ipv6: sr: Add documentation for seg_flowlabel sysctl")
Signed-off-by: Nicolas Dichtel <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/networking/ip-sysctl.rst

···
 ip6frag_time - INTEGER
 	Time in seconds to keep an IPv6 fragment in memory.
 
-IPv6 Segment Routing:
-
-seg6_flowlabel - INTEGER
-	Controls the behaviour of computing the flowlabel of outer
-	IPv6 header in case of SR T.encaps
-
-	 == =======================================================
-	 -1  set flowlabel to zero.
-	  0  copy flowlabel from Inner packet in case of Inner IPv6
-	     (Set flowlabel to 0 in case IPv4/L2)
-	  1  Compute the flowlabel using seg6_make_flowlabel()
-	 == =======================================================
-
-	Default is 0.
-
 ``conf/default/*``:
 	Change the interface-specific default settings.
 

Documentation/networking/seg6-sysctl.rst

···
 	* 1 - Drop SR packets without HMAC, validate SR packets with HMAC
 
 	Default is 0.
+
+seg6_flowlabel - INTEGER
+	Controls the behaviour of computing the flowlabel of outer
+	IPv6 header in case of SR T.encaps
+
+	 == =======================================================
+	 -1  set flowlabel to zero.
+	  0  copy flowlabel from Inner packet in case of Inner IPv6
+	     (Set flowlabel to 0 in case IPv4/L2)
+	  1  Compute the flowlabel using seg6_make_flowlabel()
+	 == =======================================================
+
+	Default is 0.