rockchip-gpt-img: remove path string for DTS_FILE
rockchip-gpt-img: remove path string for DTS_FILE

aarch64 kernel set KERNEL_DEVICETREE with path which should be removed.

Signed-off-by: Jacob Chen <8e4ad2556945082201a91c99684cac5c158a9317@iotwrt.com>
[fix some other minor problems]
Signed-off-by: ayaka <d9da4b1326b089e1905c19b389e4c8b735aa18ad@soulik.info>

hizukiayaka/meta-rockchip,hizukiayaka/meta-rockchip,hizukiayaka/meta-rockchip