arm: dts: k3-am625-beagleplay: Fix Boot

Since commit [1] A53 u-boot proper is broken. This is because nodes
marked as 'bootph-pre-ram' are not available at u-boot proper before
relocation.

To fix this we mark all nodes in u-boot.dtsi as 'bootph-all'.

[1]
9e644284 ("dm: core: Report bootph-pre-ram/sram node as pre-reloc after relocation")

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