MIPS: Netlogic: SWIOTLB dma ops for 32-bit DMA

Add SWIOTLB config option and related files to Netlogic platform.

Some XLP SoC components like the SD/MMC interface cannot do DMA beyond
32-bit physical address. The SD/MMC driver can use memory outside this
range for IO, to support this we have to add bounce buffers implemented
by SWIOTLB.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: Ganesan Ramalingam <ganesanr@broadcom.com>
Patchwork: https://patchwork.linux-mips.org/patch/5410/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/netlogic/common/Makefile

@@ -1,3 +1,4 @@
 obj-y				+= irq.o time.o
+obj-y				+= nlm-dma.o
 obj-$(CONFIG_SMP)		+= smp.o smpboot.o
 obj-$(CONFIG_EARLY_PRINTK)	+= earlycons.o