MLK-22904: ARM: imx_v6_v7_defconfig: add DMA_CMA support

This is needed for VPU/MM/GPU features.
Generated by savedefconfig.

NOTE: the exist CONFIG_CMA_SIZE_MBYTES=320 option actually did not work
before due to missing CONFIG_DMA_CMA, removed it first.

Reviewed-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>

arch/arm/configs/imx_v6_v7_defconfig

@@ -57,6 +57,7 @@ CONFIG_MODVERSIONS=y
 CONFIG_MODULE_SRCVERSION_ALL=y
 # CONFIG_BLK_DEV_BSG is not set
 CONFIG_BINFMT_MISC=m
+CONFIG_CMA=y
 CONFIG_NET=y
 CONFIG_PACKET=y
 CONFIG_UNIX=y
@@ -526,7 +527,7 @@ CONFIG_CRC_CCITT=m
 CONFIG_CRC_T10DIF=y
 CONFIG_CRC7=m
 CONFIG_LIBCRC32C=m
-CONFIG_CMA_SIZE_MBYTES=320
+CONFIG_DMA_CMA=y
 CONFIG_FONTS=y
 CONFIG_FONT_8x8=y
 CONFIG_FONT_8x16=y