BACKPORT: msm: sensor: validating the flash initialization parameters

Copying the flash initialization parameters from userspace memory to
kernel memory and in turn checking for the validity of the flash
initialization parameters pointer sent from userspace.

CRs-Fixed: 1091603
Bug: 36251230
Change-Id: I17d57016c254fb6628844a152b0e7d45c0b23b2d
Signed-off-by: Sureshnaidu Laveti <lsuresh@codeaurora.org>
Signed-off-by: David Lin <dtwlin@google.com>