[POWERPC] Build fix for drivers/macintosh/mediabay.c

This fixes the following build error with CONFIG_BLK_DEV_IDE_PMAC=n:

<-- snip -->

...
CC drivers/macintosh/mediabay.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/macintosh/mediabay.c: In function 'check_media_bay':
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/macintosh/mediabay.c:428: error: 'struct media_bay_info' has no member named 'cd_index'
make[3]: *** [drivers/macintosh/mediabay.o] Error 1

<-- snip -->

Reported-by: Adrian Bunk <[e-mail]>
Signed-off-by: Adrian Bunk <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

drivers/macintosh/mediabay.c

···
 	int				cd_irq;
 	int				cd_retry;
 #endif
-#if defined(CONFIG_BLK_DEV_IDE_PMAC) || defined(CONFIG_MAC_FLOPPY)
+#if defined(CONFIG_BLK_DEV_IDE_PMAC)
 	int 				cd_index;
 #endif
 };
···
 	}
 }
 
+#ifdef CONFIG_BLK_DEV_IDE_PMAC
 int check_media_bay(struct device_node *which_bay, int what)
 {
 	int	i;
···
 }
 EXPORT_SYMBOL(check_media_bay);
 
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
 int check_media_bay_by_base(unsigned long base, int what)
 {
 	int	i;

include/asm-powerpc/mediabay.h

···
 #define MB_POWER	6	/* media bay contains a Power device (???) */
 #define MB_NO		7	/* media bay contains nothing */
 
-int check_media_bay(struct device_node *which_bay, int what);
-
 /* Number of bays in the machine or 0 */
 extern int media_bay_count;
 
···
 /* called by IDE PMAC host driver to register IDE controller for media bay */
 int media_bay_set_ide_infos(struct device_node *which_bay, unsigned long base,
 			    int irq, ide_hwif_t *hwif);
+
+int check_media_bay(struct device_node *which_bay, int what);
+
+#else
+
+static inline int check_media_bay(struct device_node *which_bay, int what)
+{
+	return -ENODEV;
+}
+
 #endif
 
 #endif /* __KERNEL__ */