arm64: dts: ls1028a: fix a compatible issue

The I2C multiplexer used on ls1028aqds is PCA9547, not PCA9847.
If the wrong compatible was used, this chip will not be able to
be probed correctly and hence fail to work.

Signed-off-by: Yuantian Tang <andy.tang@nxp.com>
Acked-by: Li Yang <leoyang.li@nxp.com>
Fixes: 8897f325 ("arm64: dts: Add support for NXP LS1028A SoC")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>