kwineffects: Fix detection of Radeon GPUs

(cherry picked from commit 3305089a)

autotests/libkwineffects/data/glplatform/amd-gallium-radeon-rx-5700-xt-4.6

+[Driver]
+Vendor=AMD
+Renderer=AMD Radeon RX 5700 XT (NAVI10, DRM 3.40.0, 5.10.9-arch1-1, LLVM 11.0.1)
+Version=4.6 (Compatibility Profile) Mesa 20.3.3
+ShadingLanguageVersion=4.60
+
+[Settings]
+LooseBinding=true
+GLSL=true
+TextureNPOT=true
+Mesa=true
+Gallium=true
+Radeon=true
+GLVersion=4,6
+GLSLVersion=4,60
+MesaVersion=20,3,3
+GalliumVersion=0,4
+DriverVersion=20,3,3
+Driver=16
+ChipClass=14
+Compositor=9

libkwineffects/kwinglplatform.cpp

@@ -853,7 +853,7 @@ void GLPlatform::detect(OpenGLPlatformInterface platformInterface)
         }
 
         // RadeonSI
-        else if (m_vendor == "X.Org" &&
+        else if ((m_vendor == "X.Org" || m_vendor == "AMD") &&
                 (m_renderer.contains("TAHITI")    ||
                  m_renderer.contains("PITCAIRN")  ||
                  m_renderer.contains("VERDE")     ||