mips/netlogic: remove swiotlb support

nlm_swiotlb_dma_ops is unused code, so the whole swiotlb support is dead.
If it gets resurrected at some point it should use the generic
swiotlb_dma_ops instead.

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

arch/mips/include/asm/netlogic/common.h

@@ -87,9 +87,6 @@ unsigned int nlm_get_cpu_frequency(void);
 extern const struct plat_smp_ops nlm_smp_ops;
 extern char nlm_reset_entry[], nlm_reset_entry_end[];
 
-/* SWIOTLB */
-extern const struct dma_map_ops nlm_swiotlb_dma_ops;
-
 extern unsigned int nlm_threads_per_core;
 extern cpumask_t nlm_cpumask;