radv: Set is_array in lowered ycbcr tex instructions.

Fixes array tests.

Fixes: 91702374d5 "radv: Add ycbcr lowering pass."
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>

src/amd/vulkan/radv_nir_lower_ycbcr_textures.c

@@ -174,6 +174,7 @@ create_plane_tex_instr_implicit(struct ycbcr_state *state,
 
 	tex->sampler_dim = old_tex->sampler_dim;
 	tex->dest_type = old_tex->dest_type;
+	tex->is_array = old_tex->is_array;
 
 	tex->op = old_tex->op;
 	tex->coord_components = old_tex->coord_components;