Fix Vulkan yes OpenGL no builds

The format conversion relies on the QOpenGLTexture header that has its
body ifdefed out with -no-opengl. However, Qt, in a very forward looking
manner, allows having Vulkan support even when OpenGL is disabled.

Assuming that the format conversion will not be used in -no-opengl
builds, put the entire function inside a #if QT_CONFIG(opengl).

Change-Id: I772e12129729d69b81159669d239ea3945a42e5a
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

src/platformsupport/vkconvenience/qvkconvenience.cpp

@@ -51,6 +51,7 @@ QT_BEGIN_NAMESPACE
     \ingroup qpa
  */
 
+#if QT_CONFIG(opengl)
 VkFormat QVkConvenience::vkFormatFromGlFormat(uint glFormat)
 {
     using GlFormat = QOpenGLTexture::TextureFormat;
@@ -211,5 +212,6 @@ VkFormat QVkConvenience::vkFormatFromGlFormat(uint glFormat)
     default: return VK_FORMAT_UNDEFINED;
     }
 }
+#endif
 
 QT_END_NAMESPACE

src/platformsupport/vkconvenience/qvkconvenience_p.h

@@ -59,7 +59,9 @@ QT_BEGIN_NAMESPACE
 class QVkConvenience
 {
 public:
+#if QT_CONFIG(opengl)
     static VkFormat vkFormatFromGlFormat(uint glFormat);
+#endif
 };
 
 QT_END_NAMESPACE