msm: secure_buffer: fix scm call argument layout

For hyp_assign calls, dest_vm_and_perm_info wrongly
defines ctx as u32 * type, while TZ expects it as u64.
This creates an inconsistency on 32bit system. Fix it.

Change-Id: I31e8e0b5e9ae240ca031f625cf7c49f1bfe165d4
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>