package/libid3tag: needs host-gperf

package/libid3tag: needs host-gperf

Since switch to debian in commit
210ccaef5784011bc035d0ae13611cb4e76f389f, host-gperf is needed to
generate frametype.c because debian/patches/add-m4-directory.patch
patches Makefile.am. As a side effect, libid3tag tries to generate
frametype.c from frametype.gperf due to following rule:

$(srcdir)/frametype.c: $(srcdir)/frametype.gperf Makefile.am
        cd $(srcdir) &&  \
        gperf -tCcTonD -K id -N id3_frametype_lookup -s -3 -k '*'  \
                frametype.gperf |  \
        sed -e 's/\(struct id3_frametype\);/\1/' |  \
        sed -e '/\$$''Id: /s/\$$//g' >frametype.c

If host-gperf is not available, frametype.c will be empty and build with
madplay will fail on:

configure:17243: checking for snd_pcm_open in -lasound
configure:17268: /home/giuliobenetti/autobuild/run/instance-3/output-1/host/bin/powerpc64-linux-gcc -o conftest -Wall -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=1  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  conftest.c -lasound  -L/home/giuliobenetti/autobuild/run/instance-3/output-1/host/bin/../powerpc64-buildroot-linux-gnu/sysroot/usr/lib -lasound  -L/home/giuliobenetti/autobuild/run/instance-3/output-1/host/bin/../powerpc64-buildroot-linux-gnu/sysroot/usr/lib -lid3tag  >&5
/home/giuliobenetti/autobuild/run/instance-3/output-1/host/opt/ext-toolchain/bin/../lib/gcc/powerpc64-buildroot-linux-gnu/8.3.0/../../../../powerpc64-buildroot-linux-gnu/bin/ld: /home/giuliobenetti/autobuild/run/instance-3/output-1/host/bin/../powerpc64-buildroot-linux-gnu/sysroot/usr/lib/libid3tag.so: undefined reference to `id3_frametype_lookup'

Fixes:
 - http://autobuild.buildroot.org/results/15a8c7f6e34b26446179c04383719ea71495403e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>