[PATCH] riscv: remove unused SBI helpers and exports

[Christoph Hellwig]

On Sat, May 29, 2021 at 04:48:56PM -0700, Palmer Dabbelt wrote:
> I know the general rule is to only take code with callers, but these are 
> defined by the SBI so I figured we'd make everyone's lives a bit easier by 
> just keeping them around.

Keeping unused code never helps anyone.  Adding code without any known
users like some of the others is even worse.  And given that sbi_ecall
is exported (and just a trivial inline asm wrapper) there is no point
in having most of the helpers at all, but that is another story.

So for now I'd suggest to merge my patch, and changing any new code
to just use sbi_ecall instead of the remove wrappes as there is no
point in bloating the core kernel with trivial wrappers only used by
a single module.