ac/surface/gfx6: Don't force a tile index for fmask.

The bpe of the fmask often differs from the bpe of the main
surface. On SI that means it has to get a different tile
index.

addrlib is capable of figuring this out itself, so just pass
-1 instead to let it know that it is not preset.

Fixes: 9bf3570fed "ac/surface/gfx6: compute FMASK together with the color surface"
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106511
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106499
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/amd/common/ac_surface.c

@@ -868,7 +868,7 @@ static int gfx6_compute_surface(ADDR_HANDLE addrlib,
 		fin.numSlices = AddrSurfInfoIn.numSlices;
 		fin.numSamples = AddrSurfInfoIn.numSamples;
 		fin.numFrags = AddrSurfInfoIn.numFrags;
-		fin.tileIndex = AddrSurfInfoOut.tileIndex;
+		fin.tileIndex = -1;
 		fout.pTileInfo = &fmask_tile_info;
 
 		r = AddrComputeFmaskInfo(addrlib, &fin, &fout);