cleanup: include/: move pwm.h to drivers/pwm.h

move pwm.h to drivers/pwm.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>
23 files changed