kernel: sem: Ensure that initial count is lesser or equal than limit

Ensure this value during static initialization (with build assertions),
and dynamic initializations through system calls.

If initial count is larger than the limit, it's possible for the count
to wraparound, causing locking issues.

Expanding the BUILD_ASSERT() macros after declaring a k_sem struct in
K_SEM_DEFINE() is necessary to support cases where a semaphore is
defined statically.

Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>