msm: camera: isp: Prevent out of bounds read

Add checks for OOB Read in new CAM_ISP_GENERIC_BLOB_TYPE_BW_CONFIG_V2
When command buffers are passed from userspace in the form of generic
blobs, the size must be validated to prevent out of bounds read.

Change-Id: Ic604c7466cf4735abe010c6134b6e4a7f7ff6b59
Signed-off-by: Raja Mallik <rmallik@codeaurora.org>