8250: microchip: pci1xxxx: Add Burst mode transmission support in uart driver for...

8250: microchip: pci1xxxx: Add Burst mode transmission support in uart driver for reading from FIFO

pci1xxxx_handle_irq reads the burst status and checks if the FIFO
is empty and is ready to accept the incoming data. The handling is
done in pci1xxxx_tx_burst where each transaction processes data in
block of DWORDs, while any remaining bytes are processed individually,
one byte at a time.

Signed-off-by: Rengarajan S <rengarajan.s@microchip.com>
Link: https://lore.kernel.org/r/20240125100006.153342-1-rengarajan.s@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>