cdrom: mark CDROMGETSPINDOWN/CDROMSETSPINDOWN obsolete

These were only implemented by the IDE CD driver, which has since
been removed.  Given that nobody is likely to create new CD/DVD
hardware (and associated drivers) we can mark these appropriately.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: https://lore.kernel.org/all/20220427132436.12795-3-paul.gortmaker@windriver.com
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20220515205833.944139-4-phil@philpotter.co.uk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Documentation/userspace-api/ioctl/cdrom.rst

@@ -718,6 +718,9 @@ CDROMPLAYBLK
 
 
 CDROMGETSPINDOWN
+	Obsolete, was ide-cd only
+
+
 	usage::
 
 	  char spindown;
@@ -736,6 +739,9 @@ CDROMGETSPINDOWN
 
 
 CDROMSETSPINDOWN
+	Obsolete, was ide-cd only
+
+
 	usage::
 
 	  char spindown

include/uapi/linux/cdrom.h

@@ -103,7 +103,7 @@
 #define CDROMREADALL		0x5318	/* read all 2646 bytes */
 
 /* 
- * These ioctls are (now) only in ide-cd.c for controlling 
+ * These ioctls were only in (now removed) ide-cd.c for controlling
  * drive spindown time.  They should be implemented in the
  * Uniform driver, via generic packet commands, GPCMD_MODE_SELECT_10,
  * GPCMD_MODE_SENSE_10 and the GPMODE_POWER_PAGE...