serial: 8250_pci: add support for ASIX AX99100

Each of the 4 PCI functions on ASIX AX99100 PCIe to Multi I/O
Controller can be configured as a single-port serial port controller.
The subvendor id is 0x1000 when configured as serial port and MSI
interrupts are supported.

Signed-off-by: Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230724083933.3173513-4-jiaqing.zhao@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>