meson: fix dependency on qemu-keymap

When qemu-keymap is not available on the host, and enable-xkbcommon
is specified, parallel make fails with:

  % make clean
  ...
  % make -j 32
  ...
  FAILED: pc-bios/keymaps/is
  ./qemu-keymap -f pc-bios/keymaps/is -l is
  /bin/sh: ./qemu-keymap: No such file or directory
  ... many similar messages ...

The code always runs find_program, rather than waiting to build
qemu-keymap, because it looks for CONFIG_XKBCOMMON in config_host
rather than config_host_data.  Making serially succeeds, by soft
linking files from pc-bios/keymaps, but that is not the desired
result for enable-xkbcommon.

Examining all occurrences of 'in config_host' for similar bugs shows one
instance in the docs, which is also fixed here.

Fixes: 4113f4cfee ("meson: move xkbcommon to meson")

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1675708442-74966-1-git-send-email-steven.sistare@oracle.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

docs/devel/kconfig.rst

@@ -306,6 +306,6 @@ variable::
 
     host_kconfig = \
       (have_tpm ? ['CONFIG_TPM=y'] : []) + \
-      ('CONFIG_SPICE' in config_host ? ['CONFIG_SPICE=y'] : []) + \
+      ('CONFIG_LINUX' in config_host ? ['CONFIG_LINUX=y'] : []) + \
       (have_ivshmem ? ['CONFIG_IVSHMEM=y'] : []) + \
       ...

pc-bios/keymaps/meson.build

@@ -33,7 +33,7 @@ keymaps = {
   'tr': '-l tr',
 }
 
-if meson.is_cross_build() or 'CONFIG_XKBCOMMON' not in config_host
+if meson.is_cross_build() or not xkbcommon.found()
   native_qemu_keymap = find_program('qemu-keymap', required: false, disabler: true)
 else
   native_qemu_keymap = qemu_keymap