Make IDE_HWIFS configurable if EMBEDDED

This lets us lop as much as 16k off an x86 build.  It's a little ugly, but
it's dead simple.  Note the fix for HWIFS < 2.

Sizing interfaces dynamically unfortunately turns out to be pretty
major surgery.

add/remove: 0/1 grow/shrink: 0/11 up/down: 0/-16182 (-16182)
function                                     old     new   delta
ide_hwifs                                  16920    1692  -15228
init_irq                                    1113     750    -363
ideprobe_init                                283     138    -145
ide_pci_setup_ports                         1329    1193    -136
save_match                                    85       -     -85
ide_register_hw_with_fixup                   367     287     -80
ide_setup                                   1364    1308     -56
is_chipset_set                                40       4     -36
create_proc_ide_interfaces                   225     205     -20
init_ide_data                                 84      67     -17
ide_probe_for_cmd640x                       1198    1183     -15
ide_unregister                              1452    1451      -1

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>