package/brltty: add missing dependency on host-pkgconf

This fixes the following error:
  ./configure: line 14978: .../host/bin/pkg-config: No such file or directory

Signed-off-by: Mario Lang <mlang@blind.guru>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/brltty/brltty.mk

@@ -11,7 +11,7 @@ BRLTTY_INSTALL_STAGING_OPTS = INSTALL_ROOT=$(STAGING_DIR) install
 BRLTTY_INSTALL_TARGET_OPTS = INSTALL_ROOT=$(TARGET_DIR) install
 BRLTTY_LICENSE_FILES = LICENSE-GPL LICENSE-LGPL
 
-BRLTTY_DEPENDENCIES = $(TARGET_NLS_DEPENDENCIES) host-autoconf
+BRLTTY_DEPENDENCIES = $(TARGET_NLS_DEPENDENCIES) host-autoconf host-pkgconf
 
 BRLTTY_CONF_OPTS = \
 	--disable-java-bindings \