iommu/exynos: Remove __init annotation from exynos_sysmmu_probe()

Exynos SYSMMU driver supports deferred probe. It happens when clocks
needed for this driver are not yet available. Typically next calls to
driver ->probe() happen before init section is free, but this is not
really guaranteed. To make if safe, remove __init annotation from
exynos_sysmmu_probe() function.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>