ARM: at91: sama5: make ov2640 as a module

OV2640 is a detachable camera that we use to test the
Image Sensor Interface. Make it as a module, it will reduce
the kernel image size.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>

arch/arm/configs/sama5_defconfig

@@ -150,7 +150,7 @@ CONFIG_MEDIA_CAMERA_SUPPORT=y
 CONFIG_V4L_PLATFORM_DRIVERS=y
 CONFIG_SOC_CAMERA=y
 CONFIG_VIDEO_ATMEL_ISI=y
-CONFIG_SOC_CAMERA_OV2640=y
+CONFIG_SOC_CAMERA_OV2640=m
 CONFIG_DRM=y
 CONFIG_DRM_ATMEL_HLCDC=y
 CONFIG_DRM_PANEL_SIMPLE=y