kconfig: introduce kconfig files

The Kconfig files were generated mostly with this script:

  for i in `grep -ho CONFIG_[A-Z0-9_]* default-configs/* | sort -u`; do
    set fnord `git grep -lw $i -- 'hw/*/Makefile.objs' `
    shift
    if test $# = 1; then
      cat >> $(dirname $1)/Kconfig << EOF
config ${i#CONFIG_}
    bool

EOF
      git add $(dirname $1)/Kconfig
    else
      echo $i $*
    fi
  done
  sed -i '$d' hw/*/Kconfig
  for i in hw/*; do
    if test -d $i && ! test -f $i/Kconfig; then
      touch $i/Kconfig
      git add $i/Kconfig
    fi
  done

Whenever a symbol is referenced from multiple subdirectories, the
script prints the list of directories that reference the symbol.
These symbols have to be added manually to the Kconfig files.

Kconfig.host and hw/Kconfig were created manually.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20190123065618.3520-27-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/scsi/Kconfig

@@ -0,0 +1,26 @@
+config SCSI
+    bool
+
+config LSI_SCSI_PCI
+    bool
+
+config MPTSAS_SCSI_PCI
+    bool
+
+config MEGASAS_SCSI_PCI
+    bool
+
+config VMW_PVSCSI_SCSI_PCI
+    bool
+
+config ESP
+    bool
+
+config ESP_PCI
+    bool
+
+config VIRTIO_SCSI
+    bool
+
+config VHOST_USER_SCSI
+    bool