[ARM] 4789/1: S3C2412: Add missing CLKDIVN register values

Add S3C2412_CLKDIVN_DVSEN and S3C2412_CLKDIVN_HALFHCLK definitions to
the S3C2412_CLKDIVN set.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>