Remove old-style supply.dev assignments common in hsmmc init

CC: Mark Brown <broonie@opensource.wolfsonmicro.com>
CC: Mike Rapoport <mike@compulab.co.il>
CC: Nishant Kamat <nskamat@ti.com>
CC: Steve Sakoman <steve@sakoman.com>
CC: Felipe Balbi <balbi@ti.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>