mach-pcm037_eet: Fix section mismatch for eet_init_devices()

This function should be marked as __init because it is used only
in the init phase.

This fix the compiler warning:
 LD      arch/arm/mach-mx3/built-in.o
 WARNING: arch/arm/mach-mx3/built-in.o(.text+0x1328): Section mismatch in reference from the function eet_init_devices() to the (unknown reference) .init.rodata:(unknown)
 The function eet_init_devices() references
 the (unknown reference) __initconst (unknown).
 This is often because eet_init_devices lacks a __initconst
 annotation or the annotation of (unknown) is wrong.

Signed-off-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>