openrisc: use the generic in-place uncached DMA allocator

Switch openrisc to use the dma-direct allocator and just provide the
hooks for setting memory uncached or cached.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 1928e061..7e94fe3 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -7,6 +7,8 @@
 config OPENRISC
 	def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_DMA_SET_UNCACHED
+	select ARCH_HAS_DMA_CLEAR_UNCACHED
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select OF
 	select OF_EARLY_FLATTREE