[ALSA] ac97_patch: compilation warning fix

This patch kills these two compilation warnings if
power management is disabled:
sound/pci/ac97/ac97_patch.h:86: warning: 'snd_ac97_restore_status'
declared 'static' but never defined
sound/pci/ac97/ac97_patch.h:87: warning: 'snd_ac97_restore_iec958'
declared 'static' but never defined

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/ac97/ac97_patch.h

@@ -83,8 +83,10 @@ static int snd_ac97_swap_ctl(struct snd_ac97 *ac97, const char *s1,
 			     const char *s2, const char *suffix);
 static void snd_ac97_rename_vol_ctl(struct snd_ac97 *ac97, const char *src,
 				    const char *dst);
+#ifdef CONFIG_PM
 static void snd_ac97_restore_status(struct snd_ac97 *ac97);
 static void snd_ac97_restore_iec958(struct snd_ac97 *ac97);
+#endif
 static int snd_ac97_info_enum_double(struct snd_kcontrol *kcontrol,
 				     struct snd_ctl_elem_info *uinfo);
 static int snd_ac97_get_enum_double(struct snd_kcontrol *kcontrol,