Add support for the CompactFlash specific PIO modes 5/6 and MWDMA modes 3/4.

Since there were no PIO5 capable hard drives produced and one would also need
66 MHz IDE clock to actually get the difference WRT the address setup timings
programmed, I decided to simply replace the old non-standard PIO mode 5 timings
with the CFA specified ones.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: stf_xl@wp.pl
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>