msm: cpr: Remove vp_data data structure

The data members of vp_data structure except step_size are not used
in  present cpr code. So, vp_data structure is removed and
step_size is added as a member of msm_cpr_config.

Change-Id: Ib8a5b87922d8ad93094b6662e066fd1df9bbda6c
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>