riscv: dts: microchip: rename icicle kit ccc clock and other minor fixes

riscv: dts: microchip: rename icicle kit ccc clock and other minor fixes

Rename the Clock Conditioning Circuit (CCC) reference clock to match
the fixed clock bindings naming recommendation.

Update the reserved memory regions in the Icicle Kit common dtsi to
use lowercase hex and drop the redundant status properties from the
memory regions, as they are not required.

Signed-off-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>