kmod: don't build documentation if not needed

No sense in building it if we throw it away in target-finalize anyway.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/kmod/kmod.mk

@@ -4,6 +4,10 @@ KMOD_SITE = $(BR2_KERNEL_MIRROR)/linux/utils/kernel/kmod/
 KMOD_INSTALL_STAGING = YES
 KMOD_DEPENDENCIES = host-pkgconf
 
+ifneq ($(BR2_HAVE_DOCUMENTATION),y)
+KMOD_CONF_OPT += --disable-manpages
+endif
+
 ifeq ($(BR2_PACKAGE_ZLIB),y)
 KMOD_DEPENDENCIES += zlib
 KMOD_CONF_OPT += --with-zlib