ARM: dts: msm: Add camss_ahb_clk to CPP section for msm8994

CPP needs clock camss_ahb_clk to run normaly on platform msm8994.
The change is needed only for this platform. This is a source
clock that drives other clocks needed by CPP. Regulator name that
powers up CPP hardware is also changed. Property "clock-name" is
restored to its previous naming.

Signed-off-by: Iliya Varadzhakov <ivarad@codeaurora.org>
Change-Id: I3c7bf37a804e1f99f52bbbed34287465c13c35d7