drawtex: resolve glDrawTexfOES extension function

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78101
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
cmake: Silence warnings about deprecated GLUT functions on MacOSX.

Too many warnings, and GLUT is not something we can easily replace.
drawtex: fixed compiler warnings related to use of eglGetProcAddress

Add proper <EGL/egl.h> include and cast in order to fix compiler
warnings related to the use of eglGetProcAddress.

Reviewed-By: Tapani Pälli <tapani.palli@intel.com>