package/kodi: add missing host-gettext dependency

A sub-component of Kodi (cpluff) needs to be autoreconf-ed, and uses
gettext, so calls to autopoint:

    [  2%] Performing autoreconf step for 'libcpluff'
    autoreconf: Entering directory `.'
    autoreconf: running: autopoint --force
    Can't exec "autopoint": No such file or directory at [...]/host/share/autoconf/Auto4te/FileUtils.pm line 345.
    autoreconf: failed to run autopoint: No such file or directory
    autoreconf: autopoint is needed because this package uses Gettext
    make[4]: *** [CMakeFiles/libcpluff.dir/build.make:121: build/cpluff/src/libcpluff-stamp/libcpluff-autoreconf] Error 1
    make[3]: *** [CMakeFiles/Makefile2:615: CMakeFiles/libcpluff.dir/all] Error 2

Add a dependency to host-gettext to bring an appropriate variant that
provides autotpoint (gettext-tiny's autopoint works like a charm, for
the curious).

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
Cc: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>