libcamera: v4l2_videodevice: Add using statement for format map

Define a using statement for the format maps returned by
V4L2Device::formats() and use it in all call sites. There is no
functional change in this patch.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/pipeline/simple/simple.cpp

@@ -275,7 +275,7 @@ int SimpleCameraData::init()
 			return ret;
 		}
 
-		std::map<V4L2PixelFormat, std::vector<SizeRange>> videoFormats =
+		V4L2VideoDevice::Formats videoFormats =
 			video_->formats(format.mbus_code);
 
 		LOG(SimplePipeline, Debug)