Documentation/ABI: Add ABI documentation for chips and sockets

Add documentation for the following sysfs files:
/sys/devices/hv_24x7/interface/chipspersocket,
/sys/devices/hv_24x7/interface/sockets,
/sys/devices/hv_24x7/interface/coresperchip
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200525104308.9814-5-kjain@linux.ibm.com

Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_24x7

@@ -22,6 +22,27 @@ Description:
 		Exposes the "version" field of the 24x7 catalog. This is also
 		extractable from the provided binary "catalog" sysfs entry.
 
+What:		/sys/devices/hv_24x7/interface/sockets
+Date:		May 2020
+Contact:	Linux on PowerPC Developer List <linuxppc-dev@lists.ozlabs.org>
+Description:	read only
+		This sysfs interface exposes the number of sockets present in the
+		system.
+
+What:		/sys/devices/hv_24x7/interface/chipspersocket
+Date:		May 2020
+Contact:	Linux on PowerPC Developer List <linuxppc-dev@lists.ozlabs.org>
+Description:	read only
+		This sysfs interface exposes the number of chips per socket
+		present in the system.
+
+What:		/sys/devices/hv_24x7/interface/coresperchip
+Date:		May 2020
+Contact:	Linux on PowerPC Developer List <linuxppc-dev@lists.ozlabs.org>
+Description:	read only
+		This sysfs interface exposes the number of cores per chip
+		present in the system.
+
 What:		/sys/bus/event_source/devices/hv_24x7/event_descs/<event-name>
 Date:		February 2014
 Contact:	Linux on PowerPC Developer List <linuxppc-dev@lists.ozlabs.org>