kernel: Remove unnecessary inclusions of asm/semaphore.h

None of these files use any of the functionality promised by
asm/semaphore.h.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

diff --cc kernel/kexec.c
Simple merge

diff --cc kernel/kthread.c
Simple merge

diff --cc kernel/module.c
Simple merge

diff --cc kernel/posix-timers.c
Simple merge

diff --cc kernel/profile.c
Simple merge

diff --cc kernel/stop_machine.c
Simple merge