trm290: cannot call ide_setup_dma()

The TRM-290 chip is *not* SFF-8038i compatible and therefore can *not* call
ide_setup_dma() -- fix this and also cleanup the code a bit...

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