package/gettext-tiny: fix install failure if path contains "m4/" string

package/gettext-tiny: fix install failure if path contains "m4/" string

When building with path containing "m4/" occurence(i.e. make
O=output-m4) gettext-tiny install recipe copies files to wrong place and
later some package using autotools fail to autoreconf(i.e. minicom).
This is due to buggy gettext-tiny Makefile install recipe where they
substitute every "m4/" in INSTALL destination path, including the "m4/"
part of our build folder. Add patch to fix this by using $(patsubst ...)
instead of $(subst m4/,,$@) to substitute only last "m4/" occurence in
path.

Fixes:
https://bugs.busybox.net/show_bug.cgi?id=12481

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>