dmaengine: zx: rename zx296702_dma.c to zx_dma.c

ZTE ZX dma driver is not ZX296702 specific.  It works for not only
ZX296702 but also other ZTE ZX family platforms like ZX296718.  Let's
rename the file to reflect that.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/Kconfig

@@ -571,12 +571,12 @@ config XILINX_ZYNQMP_DMA
 	  Enable support for Xilinx ZynqMP DMA controller.
 
 config ZX_DMA
-	tristate "ZTE ZX296702 DMA support"
+	tristate "ZTE ZX DMA support"
 	depends on ARCH_ZX || COMPILE_TEST
 	select DMA_ENGINE
 	select DMA_VIRTUAL_CHANNELS
 	help
-	  Support the DMA engine for ZTE ZX296702 platform devices.
+	  Support the DMA engine for ZTE ZX family platform devices.
 
 
 # driver files

drivers/dma/Makefile

@@ -66,7 +66,7 @@ obj-$(CONFIG_TI_CPPI41) += cppi41.o
 obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
 obj-$(CONFIG_TI_EDMA) += edma.o
 obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
-obj-$(CONFIG_ZX_DMA) += zx296702_dma.o
+obj-$(CONFIG_ZX_DMA) += zx_dma.o
 obj-$(CONFIG_ST_FDMA) += st_fdma.o
 
 obj-y += qcom/