The Synopsys DesignWare 8250 is an 8250 that has an extra interrupt that
gets raised when writing to the LCR when busy.  To handle this we need
special serial_out, serial_in and handle_irq methods.  Add a new
platform driver that uses these accessors.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This reverts commit 6b1a98d1.

It causes a build error that needs to be resolved differently.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The Synopsys DesignWare 8250 is an 8250 that has an extra interrupt that
gets raised when writing to the LCR when busy.  To handle this we need
special serial_out, serial_in and handle_irq methods.  Add a new
function serial8250_use_designware_io() that configures a uart_port with
these accessors.

Cc: Alan Cox <alan@linux.intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>