devlink: don't wrap commands in rST shell blocks

The devlink-region.rst and ice-region.rst documentation files wrapped
some lines within shell code blocks due to being longer than 80 lines.

It was pointed out during review that wrapping these lines shouldn't be
done. Fix these two rST files and remove the line wrapping on these
shell command examples.

Reported-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>