arm64: dts: add clocks for SC9860

Some clocks on SC9860 are in the same address area with syscon devices,
those are what have a property of 'sprd,syscon' which would refer to
syscon devices, others would have a reg property indicated their address
ranges.

Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>