[ARM] S3C: Do not set clk->owner field if unset

The s3c24xx_register_clock() function has been doing a test
on clk->owner to see if it is NULL, and then setting itself
as the owner if clk->owner == NULL.

This is not needed, arch/arm/plat-s3c/clock.c cannot be
compiled as a module, and even if it was, it should not be
playing with this field if it being registered from somewhere
else.

The best course of action is to remove this bit of
code completely.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>