spirv: always expose SpvCapabilityStorageImageExtendedFormats

I forgot to do this in commit 76b97d544e ("anv: enable storage image
extended formats"). Since both drivers support this now, no need for the
conditional enable.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>

src/amd/vulkan/radv_pipeline.c

@@ -192,7 +192,6 @@ radv_shader_compile_to_nir(struct radv_device *device,
 			}
 		}
 		const struct nir_spirv_supported_extensions supported_ext = {
-			.storage_image_extended_formats = true,
 		};
 		entry_point = spirv_to_nir(spirv, module->size / 4,
 					   spec_entries, num_spec_entries,