v3dv: explain why we clear certain state after a draw call

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17536>

src/broadcom/vulkan/v3dvx_cmd_buffer.c

@@ -2106,6 +2106,11 @@ v3dX(cmd_buffer_emit_gl_shader_state)(struct v3dv_cmd_buffer *cmd_buffer)
       }
    }
 
+   /* Clearing push constants and descriptor sets for all stages is not quite
+    * correct (some shader stages may not be used at all or they may not be
+    * consuming push constants), however this is not relevant because if we
+    * bind a different pipeline we always have to rebuild the uniform streams.
+    */
    cmd_buffer->state.dirty &= ~(V3DV_CMD_DIRTY_VERTEX_BUFFER |
                                 V3DV_CMD_DIRTY_DESCRIPTOR_SETS |
                                 V3DV_CMD_DIRTY_PUSH_CONSTANTS);