x86, mce: replace machine check events logged interval with ratelimit

Impact: behavior change, use common code

Use a standard leaky bucket ratelimit for the machine check
warning print interval instead of waiting every check_interval.
Also decrease the limit to twice per minute.
This interacts better with threshold interrupts because
they can happen more often than check_interval.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>