Normalize component props data using mini program syntax

@param {Object} props the props data to normalize
@return {?Object}
function normalizeProps(props) {
    Object.keys(props).forEach(k => {
        let propValue = props[k];
        if (propValue && propValue.default !==  undefined) {
            propValue.value = propValue.default;
            delete propValue.default;
        }
    });
    return props;
}