failure too boot -current where -stable succeeds

[Michael Butler]

It appears that I've tripped over a bug in the version of ACPICA merged
into -current.

10.2-stable, as of this morning, will boot.

-current, also as of this morning, fails with:

acpi0: <INTEL TR440BXA> on motherboard
ACPI: 1 ACPI AML tables successfully acquired and loaded
ACPI: Warning: AcpiEnable failed (20150818/utxfinit-177)
acpi0: Could note enable ACPI: AE_NO_ACPI_TABLES
device_attach: acpi0 attach returned 6

 ..

panic: No usable event timer  found!

 .. at which point it drops to a DDB prompt.

As far as I can tell, it appears to be an instance of this bug which was
found on 10/2

https://bugzilla.kernel.org/show_bug.cgi?id=105351

This prevents any use of -current on some older hardware not meeting
ACPICA's expectations :-(

	imb