mtd: onenand: Remove obsolete url from Kconfig help

Samsung website no longer host information about OneNAND,
delete it.
Signed-off-by: NLadislav Michl <ladis@linux-mips.org>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/onenand/Kconfig

@@ -4,8 +4,7 @@ menuconfig MTD_ONENAND
 	depends on HAS_IOMEM
 	help
 	  This enables support for accessing all type of OneNAND flash
-	  devices. For further information see
-	  <http://www.samsung.com/Products/Semiconductor/OneNAND/index.htm>
+	  devices.
 
 if MTD_ONENAND