Fix gsp synch

Fixed various issues with GSP synchronization. These include:
* Fixed a bug where the command list size was being incorrectly decoding, causing the GPU to execute invalid commands.
* Triggering the various GSP interrupts at more appropriate times.
* Setting an expected return code for RegisterInterruptRelayQueue.
Uh, feel like adding this properly? :p 
(also, please put these commands in proper order)