ide-cd: remove handler wrappers

Remove cdrom_do_newpc_cont and cdrom_start_rw_cont wrappers and pass
cdrom_transfer_packet_command to ide_execute_command directly.

There should be no functionality change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
[bart: don't move cdrom_start_packet_command() around, remove newlines]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>