qcam: viewfinder_gl: Rename YUV.vert to identity.vert

In preparation for RGB formats support, rename the identity vertex
shader from YUV.vert to identity.vert.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/qcam/viewfinder_gl.cpp

@@ -191,7 +191,7 @@ bool ViewFinderGL::createVertexShader()
 	vertexShader_ = std::make_unique<QOpenGLShader>(QOpenGLShader::Vertex, this);
 
 	/* Compile the vertex shader */
-	if (!vertexShader_->compileSourceFile(":YUV.vert")) {
+	if (!vertexShader_->compileSourceFile(":identity.vert")) {
 		qWarning() << "[ViewFinderGL]:" << vertexShader_->log();
 		return false;
 	}