ppc: qemu: Switch over to use DM ETH and PCI

ppc: qemu: Switch over to use DM ETH and PCI

At present the board supports non-DM version PCI and E1000 drivers.
Switch over to use DM ETH and PCI by:

- Rewrite the PCI address map functions using DM APIs
- Enable CONFIG_MISC_INIT_R to do the PCI initialization and
  address map
- Drop unnecessary ad-hoc config macros
- Remove board_eth_init() in the board codes

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>