configure: preserve PKG_CONFIG for subdir builds

The slirp sub-module complains about not being able to find the glib
library on cross-compiles because it is using the default pkg-config
tool (which isn't installed in our cross-build docker images).
Preserve PKG_CONFIG in our host config and pass it down to slirp.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/configure b/configure
index 397bb476e1..542f6aea3f 100755
--- a/configure
+++ b/configure
@@ -7302,6 +7302,7 @@ echo "OBJCOPY=$objcopy" >> $config_host_mak
 echo "LD=$ld" >> $config_host_mak
 echo "RANLIB=$ranlib" >> $config_host_mak
 echo "NM=$nm" >> $config_host_mak
+echo "PKG_CONFIG=$pkg_config_exe" >> $config_host_mak
 echo "WINDRES=$windres" >> $config_host_mak
 echo "CFLAGS=$CFLAGS" >> $config_host_mak
 echo "CFLAGS_NOPIE=$CFLAGS_NOPIE" >> $config_host_mak