riscv: Stop considering R_RISCV_NONE as bad relocations

Even though those relocations should not be present in the final
vmlinux, there are a lot of them. And since those relocations are
considered "bad", they flood the compilation output which may hide some
legitimate bad relocations.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Ron Economos <re@w6rz.net>
Link: https://lore.kernel.org/r/20250710-dev-alex-riscv_none_bad_relocs_v1-v1-1-758f2fcc6e75@rivosinc.com


Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>