arm64: dts: imx93: correct mediamix power

"nic_media" clock should be enabled when power on/off mediamix, otherwise
power on/off will fail. Because "media_axi_root" clock is the parent of
"nic_media" clock, so replace "media_axi_clock" clock with "nic_media"
clock in mediamix node.

Link: https://github.com/nxp-imx/linux-imx/commit/ce18e6d0071ae9df5486af8613708ebe920484be


Fixes: f2d03ba9 ("arm64: dts: imx93: reorder device nodes")
Fixes: e85d3458 ("arm64: dts: imx93: add src node")
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>