Aha. So, dont worry about the CPU power time out, it's normal since you are using NullCPUPowerManagement (nice if one day if you can move over to Native Power Management...but that's for another day!).
Unless you are using the latest & greatest Chameleon RC5 (as in latest Multibeast) with support for 5770, then you'll not get any video (or perhaps only VESA mode if booting with -x flag) unless you do more stuff. But you are using it !!
However, I've read others had problems even with Multibeast 2.4 and 5770s.
It might be that Chameleon GraphicsEnabler is using the wrong framebuffer (lost track of which version RC5 is in Multibeast, but some have Motmot); or worst case, your card's device ID is different to the ones supported in Chameleon.
See the Graphics threads on the forum, others needed to change to Vervet, Ukari or Hoolock. Easiest if you use Multibeast to load ATY_init kext. It might just work, else you can probably edit the .plist in that kext in SingleUser (console) mode to change the framebuffer.
Note that AFAIK, ATY_init is only for 32bit (versus Chameleon - when it works - can let your graphics card work when booting 64bit). So also check you are using a 32bit com.apple.Boot.plist from Multibeast.
EIDT: Just noted that you use a DSDT. You should be able to remove NullCPUPowerManagement kext. But one thing at a time!!
