package/libksba: add host variant

This is needed to support a host build of gnupg2.  It is not directly
selectable.

Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libksba/libksba.mk

@@ -13,9 +13,13 @@ LIBKSBA_CPE_ID_VENDOR = gnupg
 LIBKSBA_INSTALL_STAGING = YES
 LIBKSBA_DEPENDENCIES = libgpg-error
 LIBKSBA_CONF_OPTS = --with-gpg-error-prefix=$(STAGING_DIR)/usr
+HOST_LIBKSBA_DEPENDENCIES = host-libgpg-error
+HOST_LIBKSBA_CONF_OPTS = --with-gpg-error-prefix=$(HOST_DIR)
 
 # Force the path to "gpgrt-config" (from the libgpg-error package) to
 # avoid using the one on host, if present.
 LIBKSBA_CONF_ENV += GPGRT_CONFIG=$(STAGING_DIR)/usr/bin/gpgrt-config
+HOST_LIBKSBA_CONF_ENV += GPGRT_CONFIG=$(HOST_DIR)/bin/gpgrt-config
 
 $(eval $(autotools-package))
+$(eval $(host-autotools-package))