radv: re-enable fast depth clears for 16-bit surfaces on VI

radv: re-enable fast depth clears for 16-bit surfaces on VI

This has been disabled some months ago because it introduced
rendering issues with Shadow Of Warrier II (DXVK). This game is
no longer affected, I wonder if 824cfc1ee5e ("radv: rework the
TC-compat HTILE hardware bug with COND_EXEC") fixed the problem.
I checked The Forest on my Polaris, and it renders fine too.

According to Phillip, this gives +5.5% with Rise Of The Tomb
Raider and DXVK. This is because DXVK  uses 16-bit depth surfaces
while the native port from Feral uses 32-bit depth surfaces.

Unfortunately, Shadow Of The Tomb Raider isn't affected because
it clears each layer of a D16 array texture individually. So it
doesn't hit the fast clear path.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>