ACPI: memhotplug: Remove leftover ACPICA debug functionality

After commit 0a347644 ("ACPI / scan: Make memory hotplug drive
use struct acpi_scan_handler"), all the ACPICA debug functionality
was removed, remove the leftover ACPICA debug code.

Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>