can: janz-ican3: add documentation for existing sysfs entries

This patch adds documentation for the existing sysfs entries for the janz PCI
module.
Signed-off-by: Andreas Gröger <andreas24groeger@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Documentation/ABI/testing/sysfs-bus-pci-drivers-janz-cmodio

+What:		/sys/bus/pci/drivers/janz-cmodio/.../modulbus_number
+Date:		May 2010
+KernelVersion:	2.6.35
+Contact:	Ira W. Snyder <ira.snyder@gmail.com>
+Description:
+		Value representing the HEX switch S2 of the janz carrier board CMOD-IO or CAN-PCI2
+
+		Read-only: value of the configuration switch (0..15)

Documentation/ABI/testing/sysfs-class-net-janz-ican3

+What:		/sys/class/net/<iface>/termination
+Date:		May 2010
+KernelVersion:	2.6.35
+Contact:	Ira W. Snyder <ira.snyder@gmail.com>
+Description:
+		Value representing the can bus termination
+
+		Default: 1 (termination active)
+		Reading: get actual termination state
+		Writing: set actual termination state (0=no termination, 1=termination active)