[PATCH 1/4] serial/arc-uart: Don't index with -ve platform_device->id

probe routine could index into port[] with -ve index. The check in arc_uart_init_one() was too late. This came to light when trying to port driver to CONFIG_OF, where bydefault of-core code sets -ve platform dev id and in absence of DT serial aliases, driver would use the -ve index.

[PATCH 1/4] serial/arc-uart: Don't index with -ve platform_device-id

probe routine could index into port[] with -ve index. The check in arc_uart_init_one() was too late. This came to light when trying to port driver to CONFIG_OF, where bydefault of-core code sets -ve platform dev id and in absence of DT serial aliases, driver would use the -ve index.