alim15x3: fix CD_ROM DMA and PIO FIFO settings setup
* Setup CD_ROM DMA and PIO FIFO settings in init_chipset_ali15x3() instead
of ata66_ali15x3(). The latter is called from init_hwif_common_ali15x3()
only if DMA base exists (which insists m5529_revision > 0x20).
This changes makes CD_ROM DMA / PIO FIFO bits being set only once
and also when "idex=ata66" kernel parameter is used.
* While at it move also chip_is_1543c_e setup from ata66_ali15x3() to
init_chipset_ali15x3() and check if isa_dev exists before accessing it.