iommu/exynos: Remove invalid symbol dependency

EXYNOS_DEV_SYSMMU symbol is not defined anywhere and prevents building
the Exynos driver. Remove it.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/Kconfig

@@ -178,7 +178,7 @@ config TEGRA_IOMMU_SMMU
 
 config EXYNOS_IOMMU
 	bool "Exynos IOMMU Support"
-	depends on ARCH_EXYNOS && EXYNOS_DEV_SYSMMU
+	depends on ARCH_EXYNOS
 	select IOMMU_API
 	help
 	  Support for the IOMMU(System MMU) of Samsung Exynos application