egl: Implement EGL_NOK_swap_region

egl: Implement EGL_NOK_swap_region

This extension adds a new function which provides an alternative to
eglSwapBuffers. eglSwapBuffersRegionNOK accepts two new parameters in
addition to those in eglSwapBuffers. The new parameters consist of a
pointer to a list of 4-integer blocks defining rectangles (x, y,
width, height) and an integer specifying the number of rectangles in
the list.