iommu/exynos: Fix driver initialization sequence

Registering a SYSMMU platform driver might directly trigger initializing
IOMMU domains and performing the initial mappings. Also the IOMMU core
might use the IOMMU hardware once it has been registered with
iommu_device_register() function. Ensure that all driver resources are
allocated and initialized before the driver advertise its presence to the
platform bus and the IOMMU subsystem.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20221110154407.26531-1-m.szyprowski@samsung.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>