Bump kernel to version 4.17 and U-Boot to 2018.05.
As the dtb file has been renamed in mainline, make the necessary
adjustments in U-Boot environment and also in
BR2_LINUX_KERNEL_INTREE_DTS_NAME.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
