turnip: enable has_ccu_flush_bug workaround for a660

It seems that a660 has the same bug. Without the workaround there
are a lot of flakes with depth-stencil tests, e.g. in:
 dEQP-VK.pipeline.extended_dynamic_state.*
 dEQP-VK.renderpass.depth_stencil_write_conditions.*
 dEQP-VK.pipeline.stencil.format.d24_unorm_s8_uint.states.*

Or guaranteed failures like of:
 dEQP-VK.pipeline.render_to_image.core.2d.huge.width.r8g8b8a8_unorm_d32_sfloat_s8_uint

Enabling the workaround fixes all of them.

cc: mesa-stable

Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15548>
(cherry picked from commit 10734fb748)

.pick_status.json

@@ -212,7 +212,7 @@
         "description": "turnip: enable has_ccu_flush_bug workaround for a660",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "because_sha": null
     },
     {

src/freedreno/common/freedreno_devices.py

@@ -263,6 +263,7 @@ a6xx_gen4 = dict(
         storage_16bit = True,
         has_tex_filter_cubic = True,
         has_sample_locations = True,
+        has_ccu_flush_bug = True,
         has_cp_reg_write = False,
         has_8bpp_ubwc = False,
         has_lpac = True,