pulseaudio/ mpd: When mpd-full is selected, pulseaudio-daemon-avahi cannot be installed. In 22.03.

[dreirund]

Applies for OpenWrt git branch openwrt-22.03, building for allwinner H3:

The package mpd-full depends on pulseaudio-daemon. However, there is also a pulseaudio-daemon-avahi which seems to provide the functionality of pulseaudio-daemon as well and additionally has more functionality.

When CONFIG_PACKAGE_mpd-full=y, it is forced that CONFIG_PACKAGE_pulseaudio-daemon=y and that dependency cannot be fulfilled with CONFIG_PACKAGE_pulseaudio-daemon-avahi=y in make menuconfig.

When I thus have CONFIG_PACKAGE_pulseaudio-daemon=y (forced by mpd-full) and CONFIG_PACKAGE_pulseaudio-daemon-avahi=y (manually selected), packaging fails with conflicting files:

 * check_data_file_clashes: Package pulseaudio-daemon-avahi wants to install file /[...]/build_dir/target-arm_cortex-a7+neon-vfpv4_musl_eabi/root-sunxi/etc/init.d/pulseaudio
	But that file is already provided by package  * pulseaudio-daemon
[and so on]

I know from other packages (like wpad*), that dependencies can be fulfilled by different packages, and so I think also here pulseaudio-daemon-avahi should also be a possibility to fulfill the dependency for mpd-full, thus allowing to deselect pulseaudio-daemon if pulseaudio-daemon-avahi is selected.