Properly detect AMD and Intel drivers on ES builds as well.

(Some) AMD and Intel cards / drivers support
WGL/GLX_create_context_es2_profile as well.

src/Magnum/Context.h

@@ -214,13 +214,11 @@ class MAGNUM_EXPORT Context {
          * @see @ref DetectedDriver, @ref detectedDriver()
          */
         enum class DetectedDriver: UnsignedShort {
-            #ifndef MAGNUM_TARGET_GLES
             /** Binary AMD desktop drivers on Windows and Linux */
             AMD = 1 << 0,
 
             /** Intel desktop drivers on Windows */
             IntelWindows = 1 << 1,
-            #endif
 
             #ifndef MAGNUM_TARGET_WEBGL
             /** Binary NVidia drivers on Windows and Linux */

src/Magnum/Implementation/driverSpecific.cpp

@@ -135,7 +135,6 @@ auto Context::detectedDriver() -> DetectedDrivers {
 
     /* Apple has its own drivers */
     #ifndef CORRADE_TARGET_APPLE
-    #ifndef MAGNUM_TARGET_GLES
     /* AMD binary desktop drivers */
     if(vendor.find("ATI Technologies Inc.") != std::string::npos)
         return *_detectedDrivers |= DetectedDriver::AMD;
@@ -151,7 +150,6 @@ auto Context::detectedDriver() -> DetectedDrivers {
     if(version.find("Mesa") != std::string::npos)
         return *_detectedDrivers |= DetectedDriver::Mesa;
     #endif
-    #endif
 
     #ifndef MAGNUM_TARGET_WEBGL
     if(vendor.find("NVIDIA Corporation") != std::string::npos)