ARM: imx_v6_v7_defconfig: Enable FB_MXC_MIPI_DSI_NORTHWEST

Enable 'FB_MXC_MIPI_DSI_NORTHWEST' config by default for imx6 and imx7
series which includes the Northwest Logic MIPI DSI controller.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>

arch/arm/configs/imx_v6_v7_defconfig

@@ -312,6 +312,7 @@ CONFIG_DRM_IMX_LDB=y
 CONFIG_DRM_IMX_HDMI=y
 CONFIG_DRM_ETNAVIV=y
 CONFIG_FB_MXS=y
+CONFIG_FB_MXC_MIPI_DSI_NORTHWEST=y
 CONFIG_FB_MXC_ADV7535=y
 CONFIG_LCD_CLASS_DEVICE=y
 CONFIG_LCD_L4F00242T03=y