ANDROID: KVM: arm64: s2mpu: Replace DABT handler with callback

Previously the S2MPU DABT handler would be called directly from the host
DABT handler and it would look up the corresponding S2MPU device. Now the
lookup is done in the generic IOMMU DABT handler and only the actual
S2MPU register access is left to the driver itself.

Bug: 190463801
Signed-off-by: David Brazdil <dbrazdil@google.com>
Change-Id: I5236cf01b9e1dcc65a00081797a13ee92a4e263b