qseecom: Check the return value of "ion_phys"

Check for return value of "ion_phys" and handle
the error cases appropriately.

Change-Id: Ib4f24af24de2b2553ed91479f46b2f79e0be0446
Signed-off-by: Hariprasad Dhalinarasimha <hnamgund@codeaurora.org>
Signed-off-by: Zhen Kong <zkong@codeaurora.org>