intel/isl: Drop unnecessary check on 16bpp depth format

intel/isl: Drop unnecessary check on 16bpp depth format

Drop unnecessary check which allows enabling of lossless write through
compression (HiZ + CCS) for D16_UNORM format on Gen12+.

We had misleading HSD information previously which used to claim that
compression can not be supported for 16bpp format. Although BSpec does
not have any restriction for D16_UNORM format.

Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6485>