arm64: dts: ti: k3: Fixup remaining pin group node names for make dtbs checks

Fix up outstanding pingroup node names to be compliant with the
upcoming pinctrl-single schema.

Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230802040347.2264339-1-nm@ti.com


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