rockchip: rename miniarm to tinker board

Miniarm is the internal project code. Now it is officially named Tinker board.
So rename it.

Signed-off-by: Eddie Cai <eddie.cai@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/rockchip/tinker_rk3288/MAINTAINERS b/board/rockchip/tinker_rk3288/MAINTAINERS
new file mode 100644
index 0000000..cddceaf
--- /dev/null
+++ b/board/rockchip/tinker_rk3288/MAINTAINERS
@@ -0,0 +1,6 @@
+TINKER-RK3288
+M:	Lin Huang <hl@rock-chips.com>
+S:	Maintained
+F:	board/rockchip/tinker_rk3288
+F:	include/configs/tinker_rk3288.h
+F:	configs/tinker-rk3288_defconfig