ARM: pxa: fix build issue on cm-x300

arch/arm/mach-pxa/cm-x300.c:716:3: error: unknown field ‘dev’ specified
in initializer
make[1]: *** [arch/arm/mach-pxa/cm-x300.o] Error 1
make: *** [arch/arm/mach-pxa] Error 2

It's caused by 'dev' field removed from struct
regulator_consumer_supply.

Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>