qseecom: Check if SG list PA is under 32bit when updating buf

Client uses qseecom_send_modified_cmd() to populate request buffer
with 32bit physical address for SG list, and we need to check if SG
list PA is beyond 32bit address for both 32bit and 64bit app. This
is because if it is beyond 32bit address, then when obtaining the
low half 32bit address from the full 64bit PA and sending it to
TZ.4.0, this address is not valid and will cause memory corruption.

Change-Id: I53d101c5b4a95d3d8b5c1f98a1b44b07e1ece5a1
Signed-off-by: Zhen Kong <zkong@codeaurora.org>