ACPI: relax BAD_MADT_ENTRY check to allow LSAPIC variable length string UIDs

ACPI 3.0 appended a variable length UID string to the LAPIC structure
as part of support for > 256 processors.  So the BAD_MADT_ENTRY() sanity
check can no longer compare for equality with a fixed structure length.

Signed-off-by: Alexey Y Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>