sunxi: disp_ump: Introduce a new ioctl for UMP wrapping the whole framebuffer

There are two ioctls (GET_UMP_SECURE_ID_BUF1 and GET_UMP_SECURE_ID_BUF2)
available for similar purpose already. And they are used by xf86-video-mali
X11 DDX driver.

In order not to clash with them, we just can add a new ioctl. This ioctl is
needed for the new, soon to be announced xf86-video-sunxifb X11 DDX driver.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>