cmd64x: procfs code fixes/cleanups (take 2)

cmd64x: procfs code fixes/cleanups (take 2)

Fix several issues with the driver's procfs output:

- when testing if channel is enabled, the code looks at the "simplex" bits, not
  at the real enable bits -- add #define for the primary channel enable bit;

- UltraDMA modes 0, 1, 3 for slave drive reported incorrectly due to using the
  master drive's clock cycle resolution bit.

While at it, also perform the following cleanups:

- don't print extra newline before the first controller's dump;

- correct the chipset names (from CMDxxx to PCI-xxx)

- don't read from the registers which aren't used for dump;

- better align the table column sizes;

- rework UltraDMA mode dump code;

- remove PIO mode dump code that has never been finished;

- remove the duplicate interrupt status (the MRDMODE register bits mirror those
  those in the CFR and ARTTIM23 registers) and fold the dump into single line;

- correct the style of the ?: operators...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>