arm64: dts: ti: k3-j721e-sk: Remove firmware-name override for R5F

The firmware name for this core should stay as the default name
"j7-main-r5f0_0-fw". This is expected to by a symlink to the actual
firmware file. If one wants to use a different firmware they should
change where the symlink points. This is usually achieved with
an update-alternative or other distro specific selection mechanisms.

The actual selection is policy and does not belong in DT.
Remove this name override.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20230307180942.2719-1-afd@ti.com


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