arm64: dts: marvell: fix clocksource for CP110 slave SPI0

I2C and SPI interfaces share common clock trees within the CP110 HW block.
It occurred that SPI0 interface has wrong clock assignment in the device
tree, which is fixed in this commit to a proper value.

Fixes: c749b8d9de32 ("arm64: dts: marvell: add description for the ...")
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>