Add EGL_NOK_swap_region definition.

I couldn't find a spec for this one on the internet, but this matches
the prototype in eglmesaext.h.  The note in swap_region2 says:

    4) How is this extension an improvement over EGL_NOK_swap_region?

    RESOLVED: This extension builds on the previous
    EGL_NOK_swap_region extension by requiring that the implementation
    considers the update region provided by the application as a
    mandate rather than a hint. This allows for region-restricted
    rendering without requiring the use of preserved buffer swaps
    which may be relatively expensive for the implementation.

    Furthermore, whilst preserved swap behaviour is necessary for
    incremental rendering, many applications fully re-render modified
    surface regions and so don't require preserved swap
    behaviour. This extension provides a lighter weight surface update
    mechanism for such applications.

registry/egl.xml

@@ -1126,6 +1126,13 @@
             <param><ptype>EGLint</ptype> *<name>rects</name></param>
             <param><ptype>EGLint</ptype> <name>n_rects</name></param>
         </command>
+        <command>
+            <proto><ptype>EGLBoolean</ptype> <name>eglSwapBuffersRegionNOK</name></proto>
+            <param><ptype>EGLDisplay</ptype> <name>dpy</name></param>
+            <param><ptype>EGLSurface</ptype> <name>surface</name></param>
+            <param><ptype>EGLint</ptype> <name>numRects</name></param>
+            <param>const <ptype>EGLint</ptype> *<name>rects</name></param>
+        </command>
         <command>
             <proto><ptype>EGLBoolean</ptype> <name>eglSwapBuffersRegion2NOK</name></proto>
             <param><ptype>EGLDisplay</ptype> <name>dpy</name></param>
@@ -1862,6 +1869,11 @@
                 <enum name="EGL_PLATFORM_GBM_MESA"/>
             </require>
         </extension>
+        <extension name="EGL_NOK_swap_region" supported="egl">
+            <require>
+                <command name="eglSwapBuffersRegionNOK"/>
+            </require>
+        </extension>
         <extension name="EGL_NOK_swap_region2" supported="egl">
             <require>
                 <command name="eglSwapBuffersRegion2NOK"/>