mei: wd: rename watchdog constants to be more descriptive

1. rename defines to more be descriptive
2. remove duplicated defines from interface.h
3. add common prefix MEI_

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>