RISC-V: Move supervisor instructions after all unprivileged ones

RISC-V: Move supervisor instructions after all unprivileged ones

This location of supervisor instructions is out of place (because many other
privileged instructions are located at the tail but after the supervisor
instructions, we have many unprivileged instructions including bit
manipulation / crypto / vector instructions).

Not only that, this is harmful to implement pseudoinstructions in the latest
'P'-extension proposal (CLROV and RDOV).  This commit moves supervisor
instructions after all unprivileged instructions.

opcodes/ChangeLog:

	* riscv-opc.c (riscv_opcodes): Adjust indents.  Move supervisor
	instructions after all unprivileged instructions.