serial: 8250: Split base port operations from universal driver

Refactor base port operations into new file; 8250_port.c.

Legacy irq handling, RSA port support, port storage for universal
driver, driver definition, module parameters and linkage remain in
8250_core.c

The source file split and resulting modules is diagrammed below:

  8250_core.c ====>   8250_core.c __
              \                     \
               \                     +-- 8250.ko (alias 8250_core)
                \     8250_pnp.c  __/     (universal driver)
                 \
                  =>  8250_port.c __
                                    \
                                     +-- 8250_base.ko
                      8250_dma.c  __/     (port operations)

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index ba82c07..7f156bd 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -152,6 +152,11 @@
 unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr);
 void serial8250_tx_chars(struct uart_8250_port *up);
 unsigned int serial8250_modem_status(struct uart_8250_port *up);
+void serial8250_init_port(struct uart_8250_port *up);
+void serial8250_set_defaults(struct uart_8250_port *up);
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count);
+int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
 
 extern void serial8250_set_isa_configurator(void (*v)
 					(int port, struct uart_port *up,