move misc/mutex.h to sys/mutex.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
For systems without userspace enabled, these work the same
as a k_mutex.
For systems with userspace, the sys_mutex may exist in user
memory. It is still tracked as a kernel object, but has an
underlying k_mutex that is looked up in the kernel object
table.
Future enhancements will optimize sys_mutex to not require
syscalls for uncontended sys_mutexes, using atomic ops
instead.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>