attempt to fix UART0 mikroBUS pin swap

Attempt to fix https://github.com/jadonk/beagleconnect/issues/67

Using the emulated I2C slave we control the MB1_CTRL for UART SPDT Analog Switch.Two endpoints are added to set the UART switch state and also to get the current state through the I2C slave

Corresponding Zephyr PR : https://github.com/jadonk/zephyr/pull/14