ide: fix PowerMac bootup oops

PowerMac bootup with CONFIG_IDE=y oopses in ide_pio_cycle_time():
because "ide: try to use PIO Mode 0 during probe if possible" causes
pmac_ide_set_pio_mode() to be called before drive->id has been set.

Bart points out other places which now need drive->id set earlier,
so follow his advice to allocate it in ide_port_alloc_devices()
(using kzalloc_node, without error message, as when allocating drive)
and memset it for reuse in ide_port_init_devices_data().

Fixed in passing: ide_host_alloc() was missing ide_port_free_devices()
from an error path.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Joao Ramos <joao.ramos@inov.pt>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>