[RFC PATCH 1/3] riscv: Correctly print supported extensions

[Tsukasa OI]

On 2021/11/22 21:14, Ben Dooks wrote:
> 
> Maybe add a warn on if there are bits set between 26 and BITS_PER_LONG ?
> 

I think that's not necessary  because riscv_isa[0] and elf_hwcap on the
current parser will not have higher bits.  This commit is just for future-
proofing (not to break anything when we extend feature bits) and adding
warning message now feels a bit ... too much.