ARM: mach-pcm038: Fix field name of regulator_consumer_supply struct

Building imx_v4_v5_defconfig generates the following error:

arch/arm/mach-imx/mach-pcm038.c:236: error: unknown field 'dev' specified in initializer
make[1]: *** [arch/arm/mach-imx/mach-pcm038.o] Error 1

Fix it by providing the correct "dev_name" field name.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>