msm: cpp: Add bus client to cpp driver

In all platforms till msm8936, CPP driver uses ISP's
bus client to update bus bandwidth. The main reason
is that CPP does not have bus master. In platforms
msm8936 and msm8994 it has its own bus master, defined
as MSM_BUS_MASTER_CPP. In order to use it, CPP driver
has to define its own bus client and operate with it.

Change-Id: I11c62ec9ef52a17f1c177984d4aca3b8c73fe468
Signed-off-by: Iliya Varadzhakov <ivarad@codeaurora.org>
Signed-off-by: Shilpa Mamidi <shilpam@codeaurora.org>