ide: push pc callback pointer into the ide_drive_t structure

Refrain from carrying the callback ptr with every packet command since the
callback function is only one anyways. ide_drive_t is probably not the most
suitable place for it right now but is the more sane solution. Besides, these
structs are going to be reorganized anyways during the generic ide rewrite.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

include/linux/ide.h

@@ -308,7 +308,7 @@ struct ide_acpi_drive_link;
 struct ide_acpi_hwif_link;
 #endif
 
-typedef struct ide_drive_s {
+struct ide_drive_s {
 	char		name[4];	/* drive name, such as "hda" */
         char            driver_req[10];	/* requests specific driver */
 
@@ -400,7 +400,12 @@ typedef struct ide_drive_s {
 	struct list_head list;
 	struct device	gendev;
 	struct completion gendev_rel_comp;	/* to deal with device release() */
-} ide_drive_t;
+
+	/* callback for packet commands */
+	void (*pc_callback)(struct ide_drive_s *);
+};
+
+typedef struct ide_drive_s ide_drive_t;
 
 #define to_ide_device(dev)container_of(dev, ide_drive_t, gendev)