arm64: dts: renesas: hihope-rev4: Add a comment explaining switch SW2404

Switch SW2404 should be at position 1 so that the clock output from
CS2000 is connected to AUDIO_CLKB_A.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Link: https://lore.kernel.org/r/20201105121127.11830-1-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>