hasvk: Make a batch decoder for each queue family

The decoder context needs to know what engine it's associated with.
Nowadays, we have render, compute, blitter, even video engines being
used from the same driver.  Rather than trying to have a single decoder
and thwacking the engine field back and forth between calls, we make
one per queue family, and stash a pointer in anv_queue for easy access.

(Ported from anv: 79caf8a44b682f731c0fd3b941f38cc1869efe2d)

[dancingmirrors: Adapted for elk.]

src/intel/vulkan_hasvk/anv_private.h

@@ -949,6 +949,8 @@ struct anv_queue {
 
    const struct anv_queue_family *           family;
 
+   struct intel_batch_decode_ctx *           decoder;
+
    uint32_t                                  exec_flags;
 
    /** Synchronization object for debug purposes (DEBUG_SYNC) */
@@ -1067,7 +1069,7 @@ struct anv_device {
 
     pthread_mutex_t                             mutex;
 
-    struct intel_batch_decode_ctx               decoder_ctx;
+    struct intel_batch_decode_ctx               decoder[ANV_MAX_QUEUE_FAMILIES];
     /*
      * When decoding a anv_cmd_buffer, we might need to search for BOs through
      * the cmd_buffer's list.