drm/v3d: Skip CSD when it has zeroed workgroups

In the Linux kernel, the following vulnerability has been resolved:

drm/v3d: Skip CSD when it has zeroed workgroups

A compute shader dispatch encodes its workgroup counts in the CFG0..CFG2

registers. Kicking off a dispatch with a zero count in any of the three

dimensions is invalid. First, the hardware will process 0 as 65536,

while the user-space driver exposes a maximum of 65535. Over that, a

submission with a zeroed workgroup dimension should be a no-op.

These zeroed counts can reach the dispatch path through an indirect CSD

job, whose workgroup counts are only known once the indirect buffer is

read and may legitimately be zero, but such scenario should only result in

a no-op.

Overwrite the indirect CSD job workgroup counts with the indirect BO

ones, even if they are zeroed, and don't submit the job to the hardware

when any of the workgroup counts is zero, so the job completes immediately

instead of running the shader.