sys/boot/fdt/dts/riscv
-> stand/boot/fdt/dts

sys/boot/ficl/riscv
-> we removed ficl, so it has to be hacked into "dloader", i guess

sys/cddl/compat/opensolaris/sys
sys/cddl/contrib/opensolaris/uts/common/sys
-> i _assume_ these two are for zfs and not needed on dfly

sys/conf
-> all files ending in .riscv would go into sys/platform/riscv without
   .riscv suffix

sys/dev/hwpmc
-> we don't have hwpmc, so not necessary

sys/riscv/conf
sys/riscv/htif
sys/riscv/riscv
-> These 3 should either go into sys/platform/riscv or into sys/cpu/riscv,
   depends how riscv platform is structured. we have sys/platform and sys/cpu.
   i'm afraid you have to study how we have split machine/platform specific
   kernel files

sys/sys
-> same directory, this is stuff that ends up in /usr/include/sys