arm64: dts: freescale: imx8-ss-dma: set lpspi0 max frequency to 60mhz

60MHz is the maximum frequency mentioned in the datasheet for
master mode. Set that to 60MHz to match lpspi2.

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>