icside: use ->init_dma method

* Add 'const struct ide_port_info *d' argument to icside_dma_init().

* Make icside_dma_init() return an error value and add icside_dma_off_init()
  (->init_dma implementation for case when DMA cannot be enabled).

* Convert the driver to use ->init_dma method.

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>