parport: do not check portlist when using device-model

We do not need to maintain a list of ports when we are using the
device-model. The base layer is going to maintain the list for us and
we can get the list of ports just using bus_for_each_dev().

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/r/20191016144540.18810-2-sudipm.mukherjee@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>