arm64: dts: ti: am65x: Add missing power-supply for Rocktech-rk101 panel

Add the 5v0 supply that is provided over the display panel cable and
used by the LCD. This is required by "simple panels" or we get the
following warning from DTBS_CHECK:

k3-am654-gp-evm.dtb: display0: 'power-supply' is a required property

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20250421214620.3770172-4-afd@ti.com


Signed-off-by: Nishanth Menon <nm@ti.com>