Fix deserialization of Table const type

Fixed dDeserialization of Table const to have either I8
or I16 element types based on input element type
eventhough table const is always serialized as int16_t values.

Signed-off-by: Tai Ly <tai.ly@arm.com>
Change-Id: I5d9972ba6a97a709003d73741c91bab31be06cf7