omap: rx51: Use REGULATOR_SUPPLY macro when initializingregulator consumers

There is REGULATOR_SUPPLY macro available for initializing the struct
regulator_consumer_supply so use it where applicable (all other supplies
than vdds_sdi) as it improves the readability.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>