Add host-pkg-config to linux configuration

In case of passing pkg_config also set host_pkg_config
otherwise pkg-config for sysroot will inject sysroot root libdir
linker flag during host build which leads to weird errors.

Change-Id: I57f277e500ba175687f65b9947b9f9c8edd969fc
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

src/core/config/linux.pri

@@ -119,6 +119,7 @@ host_build {
         # Strip '>2 /dev/null' from $$pkgConfigExecutable()
         PKGCONFIG = $$first($$list($$pkgConfigExecutable()))
         gn_args += pkg_config=\"$$PKGCONFIG\"
+        gn_args += "host_pkg_config=\"pkg-config\""
     }
 
     qtConfig(system-zlib): use?(system_minizip): gn_args += use_system_zlib=true use_system_minizip=true