[ARM] 4985/1: S3C2412: Fix ARMDIVN name in CLKDIVN definition.

Fix the name of the S3C2412_CLKDIVN_ARMDIVN define.

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