radv: advertise VK_NV_cooperative_matrix2/cooperativeMatrixConversions behind an env var

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34793>

src/util/00-radv-defaults.conf

@@ -42,6 +42,7 @@ Application bugs worked around in this file:
             <option name="radv_zero_vram" value="true" />
             <option name="radv_disable_aniso_single_level" value="true" />
             <option name="radv_disable_trunc_coord" value="true" />
+            <option name="radv_cooperative_matrix2_nv" value="true" />
         </engine>
 
         <engine engine_name_match="DXVK">

src/util/driconf.h

@@ -788,6 +788,10 @@
    DRI_CONF_OPT_B(radv_disable_hiz_his_gfx12, def, \
                   "Disable HiZ/HiS on GFX12 (RDNA4) to workaround a hw bug that causes random GPU hangs")
 
+#define DRI_CONF_RADV_COOPERATIVE_MATRIX2_NV(def) \
+   DRI_CONF_OPT_B(radv_cooperative_matrix2_nv, def, \
+                  "Expose VK_NV_cooperative_matrix2 on supported hardware.")
+
 /**
  * \brief ANV specific configuration options
  */