BACKPORT: FROMLIST: iommu/arm-smmu-v3-kvm: Add function to topup IOMMU allocator

The hypervisor returns requests for memory allocation in HVCs
encoded in the return registers.

Add a function that checks those returns and topup the IOMMU
alloctor in response to requests, and a macro that calls
this function around calling an HVC.

Link: https://lore.kernel.org/all/20241212180423.1578358-49-smostafa@google.com/



Bug: 357781595
Bug: 384432312

Change-Id: I0f503d3bcd904e0a847a5c0ba809e8e902737d4a
Signed-off-by: Mostafa Saleh <smostafa@google.com>