With DDR4, Intel SOCs take quite a long time to init their memory. During
this time, if the user is watching, it looks like SPL has hung. Add a
message in this case.
This works by adding a return code to fspm_update_config() that indicates
whether MRC data was found and a new property to the device tree.
Also add one more debug message while starting.
Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com> Tested-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>