arm64: dts: ti: Refactor J784s4-evm to a common file

Refactor J784s4-evm to a common file which uses the
superset device to allow reuse in j742s2-evm which uses the subset part.

Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>
Reviewed-by: Beleswar Padhi <b-padhi@ti.com>
Link: https://lore.kernel.org/r/20240902-b4-upstream-j742s2-v6-2-6a7aa2736797@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>