v3d: Always set up the qregs for CSD payload.

v3d: Always set up the qregs for CSD payload.

We were failing to set up payload[1] for use by LocalInvocationIndex/ID
and shared variable accesses if gl_WorkGroupID/gl_GlobalInvocationID
wasn't used (possibly because you only have one workgroup).  You're always
going to use payload[1], and payload[0] is common enough and we have DCE
in the backend to clean it up if it happens to not be used.