ACPI: EC: Some hardware requires burst mode to operate properly

Burst mode temporary (50 ms) locks EC to do only transactions with
driver, without it some hardware returns abstract garbage.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9341



Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>