board: beagle: beagleboneai64: Set fdtfile from C code instead of findfdt script

Stop using the findfdt script and switch to setting the fdtfile from C
code.

Reviewed-by: Jonathan Humphreys <j-humphreys@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Nishanth Menon <nm@ti.com>

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>

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>