I want to use GPIO in Raspberry Pi to control motor. Is there any program in webOS???? like arduino program or AVR program.
Not sure it supports GPIO interface as other OS for raspberry pi. But on the other hands, you may be able to access GPIO with mmap.
see https://memnoth.github.io/2016/05/beagleboard-handle-gpio-by-mmap-01/ although it is about beaglebone black, but I don't think there is a difference between bbb and rpi3.
I haven't tried it (i don't have a Pi), but there is a nodejs library for Pi GPIO access, so you should be able to write something as a node-service for it.
There is a thread regarding that here:
If we have webos service to control GPIO, it's awesome 
Not support it at this time.