ARM: S5PC1XX: Register pd0 and hd0 clocks, remove unecessary dummy_enable

The clk_hd0 and clk_pd0 where given a local dummy_enable call due to
not being registered with the clock code, which they really should have
been. Register these two clocks and remove the clk_dummy_enable as this
is done by the default clock registration code.

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