fix a shutdown regression in intel_idle

Fix a shutdown regression caused by 2a2d31c8 ("intel_idle: open
broadcast clock event").  The clockevent framework can automatically
shutdown broadcast timers for hotremove CPUs.  And we get a shutdown
regression when we shutdown broadcast timer for hot remove CPU, so just
delete some code.

Also fix some section mismatch.

Reported-by: Ari Savolainen <ari.m.savolainen@gmail.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>