sunxi: Add defconfig and dts file for the Orange Pi PC Plus SBC

There is a new Orange Pi PC *Plus* version available now,
this is an extended version of the regular Orange Pi PC
with sdio wifi and an eMMC.

The upstream kernel devs have decided that they want a separate
dts for the PC Plus rather then sharing a single dts between the
regular PC and the PC Plus. So add a new orangepi_pc_plus_defconfig
to match.

The added dts file matches the one submitted to the upstream kernel.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/board/sunxi/MAINTAINERS b/board/sunxi/MAINTAINERS
index 0dc84f6..de719cd 100644
--- a/board/sunxi/MAINTAINERS
+++ b/board/sunxi/MAINTAINERS
@@ -59,6 +59,7 @@
 F:	configs/orangepi_lite_defconfig
 F:	configs/orangepi_one_defconfig
 F:	configs/orangepi_pc_defconfig
+F:	configs/orangepi_pc_plus_defconfig
 F:	configs/orangepi_plus_defconfig
 F:	configs/polaroid_mid2407pxe03_defconfig
 F:	configs/polaroid_mid2809pxe04_defconfig