8250_pci: add -ENODEV code for Intel EG20T PCH

Intel EG20T PCH has UART device which is compatible with 8250.
Currently, with general configuration, the PCH UART driver is not loaded
but 8250 standard driver is loaded.  Therefore, in case of using PCH
UART driver, need to disable 8250 pci function.  However, this procedure
is not best solution.  This patch, in 8250_pci, if the device is the PCH
or the family IOH, '-ENODEV' is returned.  As a result, disabling
8250-pci processing becomes unnecessary.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>