Fix pci_io_handle allocation routines.

Fix pci_io_handle allocation routines.

The previous version of new_io_handle()  would invalidate all previous
allocations when realloc moves the base pointer of the ios array.
Since I cannot figure out where this array is useful, just get rid of
it, providing sound stable memory allocation.

Fixes vgaHWSaveFonts() in 1.12 xserver on OpenBSD, but other
sub-systems relaying on pci_io could be affected too.

Signed-off-by: Matthieu Herrb <matthieu.herrb@laas.fr>
Tested-by: Tormod Volden <debian.tormod@gmail.com>