lctr-b2xx/patches/linux: Added device-tree file patch for uart2,4 and gpio

This creates two new device-trees for lctr-b2xx.

am335x-lctr-b2xx-ntnu-gpio: Enables UART4. GPIO_0[2] (gpio 2, pin 22) as input, pulldown. GPIO_0[3] (gpio 3, pin 21) as output, pulldown.
am335x-lctr-b2xx-ntnu-uart: Enables UART4 and UART2.