ieee1394: Kconfig menu touch-up

ieee1394: Kconfig menu touch-up

Rename and reorder some prompts and modify some help texts.
The result:

  -------------------- IEEE 1394 (FireWire) support --------------------
  *** Enable only one of the two stacks, unless you know what you are doing ***
  New FireWire stack, EXPERIMENTAL
    OHCI-1394 controllers
    Storage devices (SBP-2 protocol)
  Stable FireWire stack
    OHCI-1394 controllers
    PCILynx controller
    Storage devices (SBP-2 protocol)
      Enable replacement for physical DMA in SBP2
    IP over 1394
    raw1394 userspace interface
    video1394 userspace interface
    dv1394 userspace interface (deprecated)
    Excessive debugging output

The old prompts for reference:

  -------------------- IEEE 1394 (FireWire) support --------------------
  IEEE 1394 (FireWire) support - alternative stack, EXPERIMENTAL
    Support for OHCI FireWire host controllers
    Support for storage devices (SBP-2 protocol driver)
  IEEE 1394 (FireWire) support
    *** Subsystem Options ***
    Excessive debugging output
    *** Controllers ***
    Texas Instruments PCILynx support
    OHCI-1394 support
    *** Protocols ***
    OHCI-1394 Video support
    SBP-2 support (Harddisks etc.)
      Enable replacement for physical DMA in SBP2
    IP over 1394
    OHCI-DV I/O support (deprecated)
    Raw IEEE1394 I/O support

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>