qseecom: fix memory issues for qseecom kernel client APIs

qseecom kernel client APIs don't use dmabuf to get contiguous
buf from ion heap, make change to use the correctly configured
qseecom device for dma_alloc_coherent to fix allocation error;
update cache operation if dmabuf is not used; and call
dma_free_coherent() for app shutdown.

Change-Id: I1ee942c5046e7cdbc23ce69584d1e2c996958346
Signed-off-by: Zhen Kong <zkong@codeaurora.org>