arm64: dts: ti: k3-am65: Enable OSPI nodes at the board level

OSPI nodes defined in the top-level AM65x SoC dtsi files are incomplete
and may not be functional unless they are extended with pinmux and
device information.

As the attached OSPI device is only known about at the board integration
level, these nodes should only be enabled when provided with this
information.

Disable the OSPI nodes in the dtsi files and only enable the ones that
are actually pinned out on a given board.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20230810003814.85450-5-afd@ti.com


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