Inilization of time api

Signed-off-by: Tanel Dettenborn <dettenbo@cs.helsinki.fi>

Time functions

Signed-off-by: Tanel Dettenborn <dettenbo@cs.helsinki.fi>

Most of time api functions implemented

Fixed logical errors

Signed-off-by: Tanel Dettenborn <dettenbo@cs.helsinki.fi>

Deleted function declaration and fixed a couple of errors

Signed-off-by: Tanel Dettenborn <dettenbo@cs.helsinki.fi>

Fixed/Improved TEE_wait function

Signed-off-by: Tanel Dettenborn <dettenbo@cs.helsinki.fi>