ASoC: Add __devinit annotation for pxa2xx_ac97_probe

This fixes below build warning:
WARNING: vmlinux.o(.text+0x1e632c): Section mismatch in reference from the function pxa2xx_ac97_probe() to the function .devinit.text:pxa2xx_ac97_hw_probe()
The function pxa2xx_ac97_probe() references
the function __devinit pxa2xx_ac97_hw_probe().
This is often because pxa2xx_ac97_probe lacks a __devinit
annotation or the annotation of pxa2xx_ac97_hw_probe is wrong.

Also rename pxa_ac97_dai to pxa_ac97_dai_driver to fix below build warning:

  LD      sound/soc/pxa/built-in.o
WARNING: sound/soc/pxa/built-in.o(.data+0x18c): Section mismatch in reference from the variable pxa_ac97_dai to the function .devinit.text:pxa2xx_ac97_probe()
The variable pxa_ac97_dai references
the function __devinit pxa2xx_ac97_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>