serial: abstraction for 8250 legacy ports

Not every platform that has generic legacy 8250 ports manages to have them
clocked the right way or without errata. Provide a generic interface to
allow platforms to override the default behaviour in a manner that dumps
the complexity in *their* code not the 8250 driver.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index bf9c2bd..97f5b45 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -81,4 +81,8 @@
 extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
 			     unsigned int oldstate);
 
+extern void serial8250_set_isa_configurator(void (*v)
+					(int port, struct uart_port *up,
+						unsigned short *capabilities));
+
 #endif