qseecom: Remove the dead code from driver

For kernel clients, some of the flags are maintained which is not required
as those are specific to userspace clients. So remove the code which is
not required.

Change-Id: If7fb51cc17e9a8c0f3c2632e9c42d84489bda4f6
Signed-off-by: Mallikarjuna Reddy Amireddy <mamire@codeaurora.org>