trm290: add IDE_HFLAG_TRM290 host flag

* Add IDE_HFLAG_TRM290 host flag and use it in ide_build_dmatable().

* Remove no longer needed ide_trm290 chipset type.

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