clk: qcom: clock-cpu-8994: Fix PLL rate refusal window during boot

The PLL ping-pong scheme is implemented by having the
PLL reject a round_rate request when it is prepared.
During boot, there may be a small window where both PLLs
are prepared, and this neither PLL will satisfy a
round_rate request. Fix this by ensuring both PLLs are
off in early_init. We're switching to the GPLL0 source
anyway, so there's no harm in turning off the CPU PLLs.

Change-Id: I7d4bd60bdbfb1b8687e76be55dee373742d1a1f2
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>