Possible issue with PSUART driver and receiver buffer

[mpv89]

There might be a possible problem in the PSUART driver interrupt.
When receiving data the buffer can be full and this won't empty the RX FIFO
Also, in the recv() function the DMA range request might be too small and not all bytes will be read from the RX FIFO. There is no code to take this into account and request another buffer if there is a rollover. I believe this is fine if the IRQ gets triggered immediately after but it needs verification.