qcom: secure_buffer: Use enum type to hold VMID definitions

Using a enum allows easier maintence by automatically updating the
value of VMID_LAST whenever a new value is added.

Change-Id: I35e38b9331bb10cc4725b9d9e2f65add21e58765
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
1 file changed