serial: 8250_pci: make option visible

Hiding tristate options with "if EXPERT" is usually not a good idea.
You can decide that the driver should be included by default, but you
don't know if the user wants it built-in or as a module. Hiding the
option prevents the user from making that decision.

In this specific case, driver 8250_pci ends up being built-in as soon
as SERIAL_8250=y. It is very common for distribution kernels to build
the subsystem core code into the kernel, because almost everybody
will need it, but build all the device drivers as modules. This
should be made possible.

So drop the "if EXPERT" and make SERIAL_8250_PCI visible.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>