x86, MCE: Remove bios_cmci_threshold sysfs attribute

x86, MCE: Remove bios_cmci_threshold sysfs attribute

450cc201038f3 ("x86/mce: Provide boot argument to honour bios-set CMCI
threshold") added the bios_cmci_threshold sysfs attribute which was
supposed to communicate to userspace tools that BIOS CMCI threshold has
been honoured.

However, this info is not of any importance to userspace - it should
rather get the actual error count it has been thresholded already from
MCi_STATUS[38:52].

So drop this before it becomes a used interface (good thing we caught
this early in 3.7-rc1, right after the merge window closed).

Cc: Naveen N. Rao <[email protected]>
Acked-by: Tony Luck <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Borislav Petkov <[email protected]>