egl/main: Fix eglMakeCurrent when releasing context from current thread.

egl/main: Fix eglMakeCurrent when releasing context from current thread.

EGL 1.4 Specification says that
eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT)
can be used to release the current thread's ownership on the surfaces
and context.

MESA's egl implementation was only accepting the parameters when the
KHR_surfaceless_context extension is supported.

[chadv] Add quote from the EGL 1.4 spec.
Cc: "10,1, 10.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>