arch: hexagon: Kconfig: add HAVE_DMA_ATTR in Kconfig and remove "linux/dma-mapping.h" from "asm/dma-mapping.h"

When HAS_DMA, and also need use generic implementation, HAVE_DMA_ATTR
must be enabled, or can not pass compiling with allmodconfig, the
related error:

    CC [M]  drivers/ata/libata-core.o
  drivers/ata/libata-core.c: In function 'ata_sg_clean':
  drivers/ata/libata-core.c:4598:3: error: implicit declaration of function 'dma_unmap_sg' [-Werror=implicit-function-declaration]
  drivers/ata/libata-core.c: In function 'ata_sg_setup':
  drivers/ata/libata-core.c:4708:2: error: implicit declaration of function 'dma_map_sg' [-Werror=implicit-function-declaration]

"linux/dma-mapping.h" will include "asm/dma-mapping.h", so need remove
"linux/dma-mapping.h" from "asm/dma-mapping.h",

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

arch/hexagon/Kconfig

@@ -28,6 +28,7 @@ config HEXAGON
 	select GENERIC_CLOCKEVENTS_BROADCAST
 	select MODULES_USE_ELF_RELA
 	select GENERIC_CPU_DEVICES
+	select HAVE_DMA_ATTRS
 	---help---
 	  Qualcomm Hexagon is a processor architecture designed for high
 	  performance and low power across a wide variety of applications.

arch/hexagon/include/asm/dma-mapping.h

@@ -25,7 +25,6 @@
 #include <linux/cache.h>
 #include <linux/mm.h>
 #include <linux/scatterlist.h>
-#include <linux/dma-mapping.h>
 #include <linux/dma-debug.h>
 #include <linux/dma-attrs.h>
 #include <asm/io.h>