"I got you a little something" is perfectly correct. The "little" part is not literal; it simply softens the phrase. "I got you something" can sound a little serious, but "I got you a little something" implies "no need to think too much about it, it's just a gift you might like".
It sounds as if he's about to propose, and is playing down the drama. ;)
"I got you something little" is literal.