RISC-V: Sort select statements alphanumerically

Like patch b1b3f49c ("ARM: config: sort select statements alphanumerically")
, we sort all our select statements alphanumerically by using the perl
script in patch b1b3f49c as above.

As suggested by Andrew Morton:

  This is a pet peeve of mine.  Any time there's a long list of items
  (header file inclusions, kconfig entries, array initalisers, etc) and
  someone wants to add a new item, they *always* go and stick it at the
  end of the list.

  Guys, don't do this.  Either put the new item into a randomly-chosen
  position or, probably better, alphanumerically sort the list.

Suggested-by: Zong Li <zong.li@sifive.com>
[Palmer: Re-ran the script, as there were predictably a bunch of conflicts]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>