iommu/arm-smmu-v3: Use *-y instead of *-objs in Makefile

iommu/arm-smmu-v3: Use *-y instead of *-objs in Makefile

*-objs suffix is reserved rather for (user-space) host programs while
usually *-y suffix is used for kernel drivers (although *-objs works
for that purpose for now).

Let's correct the old usages of *-objs in Makefiles.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240508151611.1444352-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Will Deacon <will@kernel.org>