Revert "pkg-config: get rid of a redundant host dep."

This reverts commit 28af8073b1.

srcpkgs/pkg-config/template

@@ -5,6 +5,8 @@ revision=2
 bootstrap=yes
 build_style=gnu-configure
 configure_args="--with-internal-glib --disable-host-tool"
+# required for gcc6 bootstrap
+hostmakedepends="gcc"
 short_desc="System for managing library compile/link flags"
 maintainer="Juan RP <xtraeme@voidlinux.org>"
 license="GPL-2"