arm64: dts: renesas: ulcb: sound clock-frequency needs descending order

Correct order of sound clock frequencies for ULCB boards
used with r8a7795 and r8a7796 SoCs.

These sounds clock frequencies are used as the ADG clock (output clocks
for audio module) initial setting and sound codec's initial system clock
which needs the maximum clock frequency. Thus, descending order is
required.

Fixes: 9f22774c ("arm64: dts: ulcb: add 12288000 for sound ADG")
Signed-off-by: Vladimir Barinov <vladimir.barinov+renesas@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
[simon: rewrote changelog]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>