libcamera: Use PixelFormat instead of unsigned int where appropriate

Use the PixelFormat instead of unsigned int where a pixel format is to
be used. PixelFormat is defined as an unsigned int but is about to be
turned into a class to add functionality.

There is no functional change in this patch.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/qcam/viewfinder.cpp

@@ -44,7 +44,7 @@ QImage ViewFinder::getCurrentImage()
 	return image_->copy();
 }
 
-int ViewFinder::setFormat(unsigned int format, unsigned int width,
+int ViewFinder::setFormat(libcamera::PixelFormat format, unsigned int width,
 			  unsigned int height)
 {
 	int ret;