fastboot flash oem SW_BINARIES_FOR_XPERIA_ANDROID_9.0_2.3.2_V9_LOIRE.img
There is no kernel-dtb-suzu in kernel/sony/msm-4.14/common-kernel, that's why. They haven't provided one yet.
You could force it to build by changing BUILD_KERNEL := false to BUILD_KERNEL :=true in /././kernel/sony/msm-4.14/common-kernel/KernelConfig.mk
It would help if "they" provided us with a more stable kernel to build in the meantime. The repo only has 4.14. Can with just clone the pie 4.9 kernel and build with that?