ARM: dts: aspeed: Add Swift BMC machine

The Swift BMC is an ASPEED ast2500 based BMC that is part of
a Power9 server. This adds the device tree description for
most upstream components.
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
Reviewed-by: Brandon Wyman <bjwyman@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/Makefile

@@ -1272,6 +1272,7 @@ dtb-$(CONFIG_ARCH_ASPEED) += \
 	aspeed-bmc-opp-lanyang.dtb \
 	aspeed-bmc-opp-palmetto.dtb \
 	aspeed-bmc-opp-romulus.dtb \
+	aspeed-bmc-opp-swift.dtb \
 	aspeed-bmc-opp-witherspoon.dtb \
 	aspeed-bmc-opp-zaius.dtb \
 	aspeed-bmc-portwell-neptune.dtb \