riscv: dts: icicle: sort nodes alphabetically

The icicle device tree is in a "random" order, so clean it up and sort
its elements alphabetically to match the newly added PolarBerry dts.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220509142610.128590-11-conor.dooley@microchip.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>