CFG_TEE_CORE_LOG_LEVEL=0 DEBUG=0 is now up in Travis

Signed-off-by: Pascal Brand <pascal.brand@st.com>
No, I've just added the "while(1)" because:
- in some case, the compiler sees the crash as a "nonreturn"
- and in others, it does not notice it.

So I added the while(1) to ensure the nonreturn.

What I can do is revert what I've done, and add an option like

    -Wno-suggest-attribute=noreturn