misc: pti, stop using iomap's unmap on ioremap space

Ioremap space is different to iomap. ->probe function uses ioremap,
but ->remove calls pci_iounmap. That one is illegal. Fix that by using
iounmap.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: J Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>