arm64: dts: imx8mn-evk: support more sample rates for wm8524 card

arm64: dts: imx8mn-evk: support more sample rates for wm8524 card

The wm8524 codec is connected to the SAI interface. There are two audio
plls on i.MX8MN, one pll can be the clock source of 44kHz series rates,
another pll can be clock source of 48kHz series rates.

Previously it only supported 48kHz series rates, with this change the
supported rates will include 44kHz series rates, from 8kHz to 192kHz.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>