freedreno/a6xx: fix kernel -> compute handling

9b2780dcaf folds the kernel path into the compute path, and then adds
a `compute -> compute` conversion that was very likely meant to be
`kernel -> compute`, so fix that.

Fixes: 9b2780dcaf ("freedreno/a6xx: Re-work fd6_emit_shader")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29458>
(cherry picked from commit b8f1e95cbe2b18e814252472a4e1407d7cb076af)

.pick_status.json

@@ -1364,7 +1364,7 @@
         "description": "freedreno/a6xx: fix kernel -> compute handling",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "9b2780dcaf486ebf91e9743251d998f97aeccde5",
         "notes": null

src/gallium/drivers/freedreno/a6xx/fd6_program.cc

@@ -119,7 +119,7 @@ fd6_emit_shader(struct fd_context *ctx, struct fd_ringbuffer *ring,
 #endif
 
    gl_shader_stage type = so->type;
-   if (type == MESA_SHADER_COMPUTE)
+   if (type == MESA_SHADER_KERNEL)
       type = MESA_SHADER_COMPUTE;
 
    enum a6xx_threadsize thrsz =