[NET]: Remove Documentation/networking/sk98lin.txt

Since the driver is gone there's no point in keeping the documentation.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/00-INDEX

@@ -84,9 +84,6 @@ policy-routing.txt
 	- IP policy-based routing
 ray_cs.txt
 	- Raylink Wireless LAN card driver info.
-sk98lin.txt
-	- Marvell Yukon Chipset / SysKonnect SK-98xx compliant Gigabit
-	  Ethernet Adapter family driver info
 skfp.txt
 	- SysKonnect FDDI (SK-5xxx, Compaq Netelligent) driver info.
 smc9.txt