Among the more than 2,000 bands that descended on the South by Southwest music festival in Austin, it’s safe to say none had quite the itinerary like Boston’s Debo Band. The 11-piece ensemble, which plays a hard-driving strain of ’70s Ethiopian music with elements of rock, funk, and experimental jazz, attended SXSW last year. This time, however, it arrived riding a wave of buzz. This could be a banner year that primes the group for a national stage.