ARM: dts: add clock data for s3c2416

This adds the clock controller itself, the xti clock on the smdk2416
as well as the clock references in the individual device nodes.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>