zorro: Let the driver core handle device enumeration

Filling in dev_name of the Zorro bus type and dev.id of each device allows
the driver core to enumerate devices, so we don't have to do that
ourselves.

This changes the names of devices in sysfs from "%02x" to "zorro%u".

Note that filling in dev.id is also needed to support MFD Zorro devices.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>