ARM: at91: dt: add Calao USB-A9G20 low power version

the low power version have a mmc-spi

eanble mmc-spi and RV3029C2 RTC in at91_dt_defconfig

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 342c1d7..ba0b00a 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -22,6 +22,7 @@
 dtb-$(CONFIG_ARCH_AT91) += kizbox.dtb
 dtb-$(CONFIG_ARCH_AT91) += tny_a9g20.dtb
 dtb-$(CONFIG_ARCH_AT91) += usb_a9g20.dtb
+dtb-$(CONFIG_ARCH_AT91) += usb_a9g20_lpw.dtb
 # sam9g45
 dtb-$(CONFIG_ARCH_AT91) += at91sam9m10g45ek.dtb
 dtb-$(CONFIG_ARCH_AT91) += pm9g45.dtb