DebugTools: make FrameProfiler compile w/o TARGET_GL enabled.

src/Magnum/DebugTools/FrameProfiler.cpp

@@ -671,6 +671,7 @@ namespace Corrade { namespace Utility {
 
 using namespace Magnum;
 
+#ifdef MAGNUM_TARGET_GL
 std::string ConfigurationValue<DebugTools::GLFrameProfiler::Value>::toString(const DebugTools::GLFrameProfiler::Value value, ConfigurationValueFlags) {
     const UnsignedInt bit = Math::log2(UnsignedShort(value));
     if(1 << bit == UnsignedShort(value))
@@ -711,5 +712,6 @@ DebugTools::GLFrameProfiler::Values ConfigurationValue<DebugTools::GLFrameProfil
 
     return values;
 }
+#endif
 
 }}

src/Magnum/DebugTools/FrameProfiler.h

@@ -703,6 +703,7 @@ MAGNUM_DEBUGTOOLS_EXPORT Debug& operator<<(Debug& debug, GLFrameProfiler::Values
 
 namespace Corrade { namespace Utility {
 
+#ifdef MAGNUM_TARGET_GL
 /**
 @configurationvalue{Magnum::DebugTools::GLFrameProfiler::Value}
 @m_since_latest
@@ -748,6 +749,7 @@ template<> struct MAGNUM_DEBUGTOOLS_EXPORT ConfigurationValue<Magnum::DebugTools
      */
     static Magnum::DebugTools::GLFrameProfiler::Values fromString(const std::string& stringValue, ConfigurationValueFlags);
 };
+#endif
 
 }}