x86, mce, cmci: remove incorrect __cpuinit/__cpuexit annotations

Impact: Bug fix on UP

The MCE code is reinitialized from resume, so we can't use
__cpuinit/__cpuexit for most of the code.  Remove those annotations
for anything downstream of mce_init().

Signed-off-by: H. Peter Anvin <hpa@zytor.com>