MAINTAINERS: Add allwinner/sunxi driver directories

These drivers are sunxi platform-specific, and so are of interest to the
sunxi maintainers.

In fact, as there is no PHY driver maintainer, drivers/phy/allwinner had
no maintainer at all.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 9f0c9f9..4d0441c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -478,6 +478,9 @@
 F:	arch/arm/include/asm/arch-sunxi/
 F:	arch/arm/mach-sunxi/
 F:	board/sunxi/
+F:	drivers/clk/sunxi/
+F:	drivers/phy/allwinner/
+F:	drivers/video/sunxi/
 
 ARM TEGRA
 M:	Tom Warren <twarren@nvidia.com>