arm64: dts: verdin-imx8mm: fix dev board audio playback

arm64: dts: verdin-imx8mm: fix dev board audio playback

[ Upstream commit 6c620a30515c494b5eeb3dc0e40d3220ea04c53b ]

Set optional `simple-audio-card,mclk-fs` parameter to ensure a proper
clock to the nau8822 audio codec. Without this change with an audio
stream rate of 44.1 kHz the playback is faster.
Set the MCLK at the right frequency, codec can properly use it to
generate 44.1 kHz I2S-FS.

Fixes: 6a57f224f734 ("arm64: dts: freescale: add initial support for verdin imx8m mini")
Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>