ARM: dts: am57xx: cl-som-am57x: update SPI Flash frequency

On-board SPI flash cat act at 48Mhz SPI bus frequency.
Update the DT frequency property.

Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Signed-off-by: Tony Lindgren <tony@atomide.com>
1 file changed