drm/amdgpu: Fix no-procfs build

Fixes undefined symbol when PROC_FS is not enabled.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202305251510.U0R2as7k-lkp@intel.com/
Fixes: 376c25f8 ("drm/amdgpu: Switch to fdinfo helper")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: <alexander.deucher@amd.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230525155227.560094-1-robdclark@gmail.com

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -2802,7 +2802,9 @@ static const struct drm_driver amdgpu_kms_driver = {
 	.dumb_map_offset = amdgpu_mode_dumb_mmap,
 	.fops = &amdgpu_driver_kms_fops,
 	.release = &amdgpu_driver_release_kms,
+#ifdef CONFIG_PROC_FS
 	.show_fdinfo = amdgpu_show_fdinfo,
+#endif
 
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,