msm-core: use get_user() API to read userspace data/settings

Currently userspace data is getting accessed directly
and leading to crash, So use get_user() API to copy
userspace data/settings to kernel space.

Change-Id: I3a75ec9503d8207829640bf88e1c3160bf72c9f0
Signed-off-by: Mohammed Khajapasha <mkhaja@codeaurora.org>