modules: fixed Find*GL*.cmake, updated coding style.

It's meaningless to have *_INCLUDE_DIR point to the dir where
{egl.h,gl2.h,gl3.h} exists, because we're always including the files
using full path (e.g. <EGL/egl.h>). It then fails miserably at compile
time on platforms which don't have the parent directory in include path.

modules/FindEGL.cmake

@@ -37,12 +37,9 @@ find_library(EGL_LIBRARY EGL)
 
 # Include dir
 find_path(EGL_INCLUDE_DIR
-    NAMES egl.h
-    PATH_SUFFIXES EGL
-)
+    NAMES EGL/egl.h)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args("EGL" DEFAULT_MSG
     EGL_LIBRARY
-    EGL_INCLUDE_DIR
-)
+    EGL_INCLUDE_DIR)

modules/FindOpenGLES2.cmake

@@ -43,12 +43,9 @@ endif()
 
 # Include dir
 find_path(OPENGLES2_INCLUDE_DIR
-    NAMES gl2.h
-    PATH_SUFFIXES GLES2
-)
+    NAMES GLES2/gl2.h)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args("OpenGLES2" DEFAULT_MSG
     ${OPENGLES2_LIBRARY_NEEDED}
-    OPENGLES2_INCLUDE_DIR
-)
+    OPENGLES2_INCLUDE_DIR)

modules/FindOpenGLES3.cmake

@@ -42,12 +42,9 @@ find_library(OPENGLES3_LIBRARY NAMES
 
 # Include dir
 find_path(OPENGLES3_INCLUDE_DIR
-    NAMES gl3.h
-    PATH_SUFFIXES GLES3
-)
+    NAMES GLES3/gl3.h)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args("OpenGLES3" DEFAULT_MSG
     OPENGLES3_LIBRARY
-    OPENGLES3_INCLUDE_DIR
-)
+    OPENGLES3_INCLUDE_DIR)