Instead of including the same list of devices for each target,
set CONFIG_PCI to true, and make the devices default to present
whenever PCI is available.  However, s390x does not want all the
PCI devices, so there is a separate symbol to enable them.

Done mostly with the following script:

  while read i; do
     i=${i%=y}; i=${i#CONFIG_}
     sed -i -e'/^config '$i'$/!b' -en \
            -e'a\' -e'    default y if PCI_DEVICES\' -e'    depends on PCI' \
          `grep -lw $i hw/*/Kconfig`
  done < default-configs/pci.mak

followed by replacing a few "depends on" clauses with "select"
whenever the symbol is not really related to PCI.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NYang Zhong <yang.zhong@intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Message-Id: <20190123065618.3520-31-yang.zhong@intel.com>
Acked-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>