xtensa build failures in -next due to DMA API changes

[Guenter Roeck <linux@roeck-us.net>]

Hi,

xtensa builds fail in -next (again) as follows.

In file included from include/linux/dma-mapping.h:86:0,
                 from include/asm-generic/pci-dma-compat.h:7,
		 from ./arch/xtensa/include/asm/pci.h:59,
		from include/linux/pci.h:1492,
		from arch/xtensa/kernel/platform.c:16:
./arch/xtensa/include/asm/dma-mapping.h:40:21:
	error: redefinition of ‘dma_alloc_attrs’

In file included from ./arch/xtensa/include/asm/dma-mapping.h:33:0,
                 from include/linux/dma-mapping.h:86,
		 from include/asm-generic/pci-dma-compat.h:7,
		from ./arch/xtensa/include/asm/pci.h:59,
		from include/linux/pci.h:1492,
		from arch/xtensa/kernel/platform.c:16:
include/asm-generic/dma-mapping-common.h:245:21:
	note: previous definition of ‘dma_alloc_attrs’ was here

and many similar errors; it looks like all dma attribute functions have been
redefined.

The problem seems to have been introduced with changes made by Christoph
Hellwig, coming in through Andrew's tree. Copying them here for comments.

Guenter