arm64: amd-seattle: Adding device tree for AMD Seattle platform

Initial revision of device tree for AMD Seattle Development platform.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Thomas Lendacky <Thomas.Lendacky@amd.com>
Signed-off-by: Joel Schopp <Joel.Schopp@amd.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9532f8d..ddc0196 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -142,6 +142,11 @@
 
 menu "Platform selection"
 
+config ARCH_SEATTLE
+	bool "AMD Seattle SoC Family"
+	help
+	  This enables support for AMD Seattle SOC Family
+
 config ARCH_THUNDER
 	bool "Cavium Inc. Thunder SoC Family"
 	help