arm64: dts: renesas: beacon-renesom: Fix audio clock rate

The WM8962 is configured so the SoC is driving the clock, and it's
currently set to 24 MHz.  However, when playing audio it shows the
following message:
    wm8962 5-001a: Unsupported sysclk ratio 500

While not harmful, a better clock ratio is 512.  It makes the
message disappear, and it still plays sound.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230114225647.227972-3-aford173@gmail.com


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