msm: acpuclock-7x30: Prepare PLLs during init

The new clk_prepare()/clk_unprepare() APIs need to be called from
non-atomic context. Since acpuclock is used in such places as
suspend/resume which is always in atomic context we must prepare
the PLLs during init or risk the chance of enabling a PLL that
isn't prepared.

Change-Id: I3a191e1750e82b443a1028fe0befa68a09089fb4
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>