rpm/check-for-config-changes: add OBJTOOL and FTRACE_MCOUNT_USE_*
    
    Dummy gcc pretends to support -mrecord-mcount option but actual gcc on
    ppc64le does not. Therefore ppc64le builds of 6.2-rc1 and later in OBS
    enable FTRACE_MCOUNT_USE_OBJTOOL and OBJTOOL config options, resulting in
    check failure.
    
    As we already have FTRACE_MCOUNT_USE_CC and FTRACE_MCOUNT_USE_RECORDMCOUNT
    in the exception list, replace them with a general pattern. And add OBJTOOL
    as well.