arm: dts: ti: omap: Fix OPP table node names

Fix the opp table node names for opps to be compliant with bindings.

Signed-off-by: Nishanth Menon <nm@ti.com>
Message-ID: <20230724153911.1376830-4-nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>