board: beagle: Add BeagleBone AI-64 support

Add base support for BeagleBone AI-64 board support.

Further information at  https://beagleboard.org/ai-64

Signed-off-by: Nishanth Menon <nm@ti.com>
diff --git a/arch/arm/mach-k3/j721e/Kconfig b/arch/arm/mach-k3/j721e/Kconfig
index d91844b..0761b82 100644
--- a/arch/arm/mach-k3/j721e/Kconfig
+++ b/arch/arm/mach-k3/j721e/Kconfig
@@ -52,6 +52,7 @@
 
 endchoice
 
+source "board/beagle/beagleboneai64/Kconfig"
 source "board/ti/j721e/Kconfig"
 
 endif