[PATCH] Build the RISC-V texinfo documentation

[Nick Clifton]

Hi Peter,

> The RISC-V documentation didn't actually work before: it wasn't even
> being built because nothing was included properly.  This patch fixes the
> syntax errors in the documentation and links everything together so it
> builds.  I also went through and added a RISC-V section wherever there
> was an RX section before.

Approved and applied.

Note - when producing these patches it really does help if you include a
ChangeLog entry as well.  Preferably as plain text rather than a context
diff.

Cheers
  Nick