this change is purely to document that they are the same in
preparation to remove the arch-specific headers for these archs and
replace them with a generic version that matches riscv32 and can be
shared by these and all future archs.
user_regs_struct and user_fp_struct were missing from the initial
commit of the port.
the union type for elf_fpreg_t and the new value of ELF_NFPREG are
made consistent with glibc.
