riscv: Enable bitops instrumentation

riscv: Enable bitops instrumentation

Instead of implementing the bitops functions directly in assembly,
provide the arch_-prefixed versions and use the wrappers from
asm-generic to add instrumentation. This improves KASAN coverage and
fixes the kasan_bitops_generic() unit test.

Signed-off-by: Samuel Holland <[email protected]>
Reviewed-by: Alexandre Ghiti <[email protected]>
Tested-by: Alexandre Ghiti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>