MIPS: remove CONFIG_DMA_PERDEV_COHERENT

Just select DMA_NONCOHERENT and ARCH_HAS_SETUP_DMA_OPS from the
MIPS_GENERIC platform instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/Kconfig

@@ -126,6 +126,7 @@ choice
 
 config MIPS_GENERIC_KERNEL
 	bool "Generic board-agnostic MIPS kernel"
+	select ARCH_HAS_SETUP_DMA_OPS
 	select MIPS_GENERIC
 	select BOOT_RAW
 	select BUILTIN_DTB
@@ -135,7 +136,7 @@ config MIPS_GENERIC_KERNEL
 	select CPU_MIPSR2_IRQ_EI
 	select CPU_MIPSR2_IRQ_VI
 	select CSRC_R4K
-	select DMA_PERDEV_COHERENT
+	select DMA_NONCOHERENT
 	select HAVE_PCI
 	select IRQ_MIPS_CPU
 	select MIPS_AUTO_PFN_OFFSET

arch/mips/mm/dma-noncoherent.c

@@ -135,7 +135,7 @@ void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
 }
 #endif
 
-#ifdef CONFIG_DMA_PERDEV_COHERENT
+#ifdef CONFIG_ARCH_HAS_SETUP_DMA_OPS
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 		const struct iommu_ops *iommu, bool coherent)
 {