perf: RISC-V: Remove non-kernel-doc ** comments

This will presumably trip up some tools that try to parse the comments
as kernel doc when they're not.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 4905ec2f

 ("RISC-V: Add sscofpmf extension support")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

--

These recently landed in for-next, but I'm trying to avoid rewriting
history as there's a lot in flight right now.

Reviewed-by: Atish Patra <atishp@rivosinc.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220322220147.11407-1-palmer@rivosinc.com


Signed-off-by: Will Deacon <will@kernel.org>