The legacy PNP IDs for NI 16550 devices (which is how 8250_pnp enumerates them) are not gated by CONFIG_SERIAL_8250_NI16550, so if you turn that option off, you end up with NI 16550s in an unfortunate partially-enumerated state because 8250_pnp finds them, but doesn't initialize them properly.
This change puts those IDs behind ifdefs so that it becomes possible to disable the existing NI 16550 driver.
The legacy PNP IDs for NI 16550 devices (which is how 8250_pnp enumerates them) are not gated by CONFIG_SERIAL_8250_NI16550, so if you turn that option off, you end up with NI 16550s in an unfortunate partially-enumerated state because 8250_pnp finds them, but doesn't initialize them properly.
This change puts those IDs behind ifdefs so that it becomes possible to disable the existing NI 16550 driver.