kbuild: drop cpuinit/cpuexit checks in modpost

With the removal of cpuinit/cpuexit we no longer need to
do section mismatch checks on these sections.

Drop it from modpost.

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
revert hacks for the previous misuse of __cpuinit for hotplug only functions

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>