vim: also install xxd

Quite a number of scripts use xxd, so install it as well.

Install it unconditionally as the size is trivial compared to vim (~10kb vs
~1.5MB).

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/vim/vim.mk

@@ -31,6 +31,7 @@ VIM_LICENSE_FILES = README.txt
 define VIM_INSTALL_TARGET_CMDS
 	cd $(@D)/src; \
 		$(MAKE) DESTDIR=$(TARGET_DIR) installvimbin; \
+		$(MAKE) DESTDIR=$(TARGET_DIR) installtools; \
 		$(MAKE) DESTDIR=$(TARGET_DIR) installlinks
 endef