freedreno/a6xx: set CHROMA_LINEAR

This seems to have no effect on a618, but restores linear filtering on
a635 when the texture is yuv.  The blob sets it on a635 as well (but not
on a618).

Fixed android.media.cts.DecodeAccuracyTest#* on a635.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19514>

src/gallium/drivers/freedreno/a6xx/fd6_texture.c

@@ -294,6 +294,13 @@ fd6_sampler_state_create(struct pipe_context *pctx,
    if (needs_border)
       so->texsamp2 = A6XX_TEX_SAMP_2_BCOLOR(get_bcolor_offset(ctx, cso));
 
+   /* We don't know if the format is going to be YUV.  Setting CHROMA_LINEAR
+    * unconditionally seems fine.
+    */
+   if (cso->mag_img_filter == PIPE_TEX_FILTER_LINEAR &&
+       cso->min_img_filter == PIPE_TEX_FILTER_LINEAR)
+      so->texsamp2 |= A6XX_TEX_SAMP_2_CHROMA_LINEAR;
+
    return so;
 }