soc: qcom: fingerprint: keep QSEE handle in kernel space

Move the QSEE handle from user space to kernel space.
In addition, fix possible overflow when checking that
the command and response buffers fit in the shared buffer.

Change-Id: I21b1866546a2825fe348a260c60e341bbe9600ea
Signed-off-by: Lior Barenboim <liorb@codeaurora.org>
Signed-off-by: Biswajit Paul <biswajitpaul@codeaurora.org>