ia64: clean up swiotlb support

Move the few remaining bits of swiotlb glue towards their callers,
and remove the pointless on ia64 swiotlb variable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian König <christian.koenig@amd.com>

arch/ia64/include/asm/dma-mapping.h

@@ -8,7 +8,6 @@
  */
 #include <asm/machvec.h>
 #include <linux/scatterlist.h>
-#include <asm/swiotlb.h>
 #include <linux/dma-debug.h>
 
 #define ARCH_HAS_DMA_GET_REQUIRED_MASK

arch/ia64/include/asm/swiotlb.h

@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef ASM_IA64__SWIOTLB_H
-#define ASM_IA64__SWIOTLB_H
-
-#include <linux/dma-mapping.h>
-#include <linux/swiotlb.h>
-
-#ifdef CONFIG_SWIOTLB
-extern int swiotlb;
-extern void pci_swiotlb_init(void);
-#else
-#define swiotlb 0
-static inline void pci_swiotlb_init(void)
-{
-}
-#endif
-
-#endif /* ASM_IA64__SWIOTLB_H */