The current version of alsa-lib (1.0.22) does not build when
--disable-pcm is used at configure time. I've reported the issue at
https://bugtrack.alsa-project.org/alsa-bug/view.php?id=4913.
In the mean time, we can prevent the user from not selecting PCM
support by using the following patch.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 config BR2_PACKAGE_ALSA_LIB
        bool "alsa-lib"
+       # Temporary until
+       # https://bugtrack.alsa-project.org/alsa-bug/view.php?id=4913
+       # is fixed
+       select BR2_PACKAGE_ALSA_LIB_PCM
        help
          The Advanced Linux Sound Architecture (ALSA) provides audio and MIDI
          functionality to the Linux operating system.