dma-mapping: fix build when !CONFIG_ARM_SMMU

Allow compilation when CONFIG_ARM_SMMU is not selected by making
CONFIG_IOMMU_IO_PGTABLE_FAST depends on CONFIG_ARM64_DMA_USE_IOMMU.
Removed inclusion of dma-mapping-fast.h by dma-iommu.h.

CRs-Fixed: 2000526
Change-Id: Iadfc236f848f46e6742a98581dbfdb13c7a2695e
Signed-off-by: Atul Raut <araut@codeaurora.org>