ABI: pps: Add ABI documentation for Intel TIO

Document sysfs interface for Intel Timed I/O PPS driver.

Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Signed-off-by: Subramanian Mohan <subramanian.mohan@intel.com>
Link: https://lore.kernel.org/r/20250219040618.70962-5-subramanian.mohan@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: subbu-m37

Documentation/ABI/testing/sysfs-pps-gen-tio

@@ -0,0 +1,6 @@
+What:		/sys/class/pps-gen/pps-genx/enable
+Date:		April 2025
+KernelVersion:	6.15
+Contact:	Subramanian Mohan<subramanian.mohan@intel.com>
+Description:
+		Enable or disable PPS TIO generator output.

MAINTAINERS

@@ -18916,6 +18916,7 @@ S:	Maintained
 W:	http://wiki.enneenne.com/index.php/LinuxPPS_support
 F:	Documentation/ABI/testing/sysfs-pps
 F:	Documentation/ABI/testing/sysfs-pps-gen
+F:	Documentation/ABI/testing/sysfs-pps-gen-tio
 F:	Documentation/devicetree/bindings/pps/pps-gpio.yaml
 F:	Documentation/driver-api/pps.rst
 F:	drivers/pps/