pci: Configure expansion ROM during auto config process

Currently PCI expansion ROM address is assigned by a call to
pciauto_setup_rom() outside of the pci auto config process.
This does not work when expansion ROM is on a device behind
PCI bridge where bridge's memory limit register was already
programmed to a value that does not cover the newly assigned
expansion ROM address. To fix this, we should configure the
ROM address during the auto config process.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>