There are at least few existing users of the proposed API which
retrieves either MEM or IO resource from platform device.

Make it common to utilize in the existing and new users.

Cc: Eric Auger <eric.auger@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: Peng Hao <peng.hao2@zte.com.cn>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201209203642.27648-1-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>