AMD's integrated graphics will handle digital audio over HDMI, but you may be limited in how many channels you can support. My AMD 785G motherboard with integrated Radeon HD4200 graphics works fine over HDMI, except that it doesn't allow 5.1 or 7.1-channel output.
Edit: If you install the Realtek version of the AMD HDMI drivers, you can enable DTS.
i7-2600K, H70, P8P67-M Pro, 16 GiB, HD7950, SSD, 3 HD, Blu-ray, X-Fi Ti Pro, Antec P182, S75CF, 3007WFP+2001FP, RK-9000BR, MX518
i5-3570K, GeminII-S524, P8Z77-M Pro, 16 GiB, HD7770, SSD, 2 HD, Blu-ray, InifiniTV4, NSK2480, 55" TV; Asus UX32VD