Move XLP PCI UART device to sys/mips/nlm/dev/ directory. Other drivers for the XLP SoC devices will be added here as well. Update uart_cpu_xlp.c and uart_pci_xlp.c use macros for uart port, speed and IO frequency.
Move XLP PCI UART device to sys/mips/nlm/dev/ directory. Other drivers for the XLP SoC devices will be added here as well. Update uart_cpu_xlp.c and uart_pci_xlp.c use macros for uart port, speed and IO frequency.