Linux Kernel Beagleboard-X15 DTS device tree

Help me to configure the Linux Kernel device tree blob to activate the MCSPI3 MCSPI4 UART8 UART9 I2C4 in the Beagleboard-X15. This corresponds to the hardware layout of my add-on board. I'm using the TI PROCESSOR-SDK-LINUX-AM57X 04_01_00_06 Build date 09272017 as Beagleboard-x15 software environment. The Linux Kernel version included in this SDK is the 4.9, provided by TI. When I went through the DTS files associated to my BeagleBoard-X15 the MCSPI and UART, I2C4 controllers are disabled by default. In Linux, I actually don't have the nodes /dev/spiXX, nor /dev/ttyXX, nor /dev/i2c4. You have to change and compile the dts file in order to open these ports. I am looking for someone with high level deep knowledge about Linux Kernel.