iommu: arm-smmu: Use same callback for thaw and restore

There is a hibernation usecase where snapshot image is captured
and system continue to work as normal without shutting down. So,
thaw should counter all the changes done by freeze callback.
Fix this by using same callback for thaw and restore.

Change-Id: I5f83db1f7c9a4e7ecebd5f8e2fedee1f2c310d3c
Signed-off-by: Arun KS <arunks@codeaurora.org>