ARC: bitops: Remove non relevant comments

commit 80f420842ff42 removed the ARC bitops microoptimization but failed
to prune the comments to same effect

Fixes: 80f420842ff42 ("ARC: Make ARC bitops "safer" (add anti-optimization)")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
1 file changed