I am working on an embedded product, for which we're looking to use the PCA9685 led driver chip. The product uses a Yocto built Linux kernel on version 4.1. There is a a driver for the PCA9685 in the current master branch of the Linux kernel source, but not in version 4.1. Will the driver from the master branch be compatible with 4.1? If not, is there a driver that is compatible?