[libata sata_promise] add correct read/write of hotplug registers for SATAII devices

This patch adds support for correctly masking out and knowing about
hotplug events on Promise SATAII150 Tx4/Tx2 Plus controllers.

Also, a kmalloc->kzalloc cleanup.

Signed-off-by: Luke Kosewski <lkosewsk@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --cc drivers/scsi/sata_promise.c
Simple merge