ide-floppy: move floppy ioctls handling to ide-floppy_ioctl.c

While at it:

- idefloppy_create_read_capacity_cmd() -> ide_floppy_create_read_capacity_cmd()
- idefloppy_create_mode_sense_cmd() -> ide_floppy_create_mode_sense_cmd()
- idefloppy_create_request_sense_cmd() -> ide_floppy_create_request_sense_cmd()
- idefloppy_create_format_unit_cmd() -> ide_floppy_create_format_unit_cmd()
- idefloppy_get_sfrp_bit() -> ide_floppy_get_sfrp_bit()

Acked-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>