iommu/exynos: Remove initconst attribute to avoid potential kernel oops

Exynos SYSMMU registers standard platform device with sysmmu_of_match
table, what means that this table is accessed every time a new platform
device is registered in a system. This might happen also after the boot,
so the table must not be attributed as initconst to avoid potential kernel
oops caused by access to freed memory.

Fixes: 6b21a5db ("iommu/exynos: Support for device tree")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>