Move the new AMD-Vi IVHD [ACPI_IVRS_HARDWARE_NEW]definitions added in r329360 in contrib ACPI to local files till ACPI code adds new definitions reported by jkim.
Rename ACPI_IVRS_HARDWARE_NEW to ACPI_IVRS_HARDWARE_EFRSUP, since new definitions add Extended Feature Register support. Use IvrsType to distinguish three types of IVHD - 0x10(legacy), 0x11 and 0x40(with EFR). IVHD 0x40 is also called mixed type since it supports HID device entries.
Fix 2 coverity bugs reported by cem.

Reported by:jkim, cem
Approved by:grehan
Differential Revision://reviews.freebsd.org/D14501