arm64: dts: imx8mp: change AUDIO_AXI_CLK_ROOT freq. to 800MHz

arm64: dts: imx8mp: change AUDIO_AXI_CLK_ROOT freq. to 800MHz

AUDIO_AXI_CLK_ROOT can't run at currently requested 600MHz w/ its parent
SYS_PLL1 configured at 800MHz. Configure it to run at 800MHz as some
applications running on the DSP expect the core to run at this frequency
anyways. This change also affects the AUDIOMIX NoC.

Fixes: b739681b3f8b ("arm64: dts: imx8mp: Fix SDMA2/3 clocks")
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
Reviewed-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>