dt-bindings: riscv: sort multi-letter Z extensions alphanumerically

dt-bindings: riscv: sort multi-letter Z extensions alphanumerically

The multi-letter extension enum is documented as being sorted
alphanumerically (see the "multi-letter extensions, sorted
alphanumerically" comment), but several Z entries have drifted out of
order.

Reorder the affected entries so the multi-letter Z list is sorted
alphanumerically again.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Guodong Xu <docular.xu@gmail.com>
Link: https://patch.msgid.link/20260701-rva23u64-hwprobe-v2-v5-1-2c61f94a695a@gmail.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>