msm: board-copper: Move clock init into msm_copper_add_drivers

The clock driver depends on rpm, rpm-smd and regulators
and needs to initialize after those drivers. Place the
clock init call at the right position in msm_copper_add_drivers.

Change-Id: Idf8c810d787140c451d9704767b805328c89c94c
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>