gigaset: move up Kconfig inclusion point

In preparation for porting to kernel CAPI subsystem, include the
Gigaset driver's Kconfig directly from ISDN's instead of I4L's.

Impact: Kconfig reorganisation, no functional change
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/i4l/Kconfig

@@ -135,5 +135,3 @@ source "drivers/isdn/act2000/Kconfig"
 source "drivers/isdn/hysdn/Kconfig"
 
 endmenu
-
-source "drivers/isdn/gigaset/Kconfig"