dts: support building all dtb files for a specific vendor

This adjusts OF_UPSTREAM to behave more like the kernel by allowing for
all the devicetree files for a given vendor to be compiled. This is
useful for Qualcomm in particular as most boards are supported by a
single U-Boot build just provided with a different DT.

Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Amlogic boards builds
diff --git a/dts/Kconfig b/dts/Kconfig
index b9b6367..6883a00 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -101,6 +101,30 @@
 	  the dts/upstream subtree, they can override this option to have the
 	  DT build from existing U-Boot tree location instead.
 
+config OF_UPSTREAM_BUILD_VENDOR
+	bool "Build all devicetree files for a particular vendor"
+	depends on OF_UPSTREAM
+	help
+	  Enable building all devicetree files for a particular vendor. This
+	  is useful for generic U-Boot configurations where many boards can
+	  be supported with a single binary.
+
+	  This is only available for platforms using upstream devicetree.
+
+config OF_UPSTREAM_VENDOR
+	string "Vendor to build all upstream devicetree files for"
+	depends on OF_UPSTREAM_BUILD_VENDOR
+	default "qcom" if ARCH_SNAPDRAGON
+	default "rockchip" if ARCH_ROCKCHIP
+	default "amlogic" if ARCH_MESON
+	default "allwinner" if ARCH_SUNXI
+	default "mediatek" if ARCH_MEDIATEK
+	default "marvell" if ARCH_MVEBU || ARCH_KIRKWOOD
+	default "xilinx" if ARCH_VERSAL || ARCH_ZYNQ
+	default "nvidia" if ARCH_TEGRA
+	help
+	  Select the vendor to build all devicetree files for.
+
 choice
 	prompt "Provider of DTB for DT control"
 	depends on OF_CONTROL