KUALA LUMPUR, May 6 (Reuters) - Indonesian airline Garuda Indonesia Tbk GIAA.JK has secured $100 million in financing from Maybank Islamic Bhd MBBMIS.UL to fund its operations and expansion, the Malaysian bank said on Tuesday.The Musyarakah-based loan, which will be Indonesia&aposs largest bilateral Islamic financing, has a tenure of 3 years and will be issued through Maybank&aposs Indonesian unit