alsa-lib: add patch to fix incorrect code dependency

alsa-lib: add patch to fix incorrect code dependency

This commit adds a patch to alsa-lib that fixes an incorrect code
dependency: some code built when MIDI support is enabled is
unconditionally referencing code that is built when SEQ support is
enabled, both options being independent.

This causes build failures such as:

/home/buildroot/buildroot-test/instance-1/output/host/arm-buildroot-linux-uclibcgnueabi/sysroot/usr/lib/libasound.a(pcm_dmix.o): In function `snd_pcm_dmix_sync_ptr':
pcm_dmix.c:(.text+0x83c): warning:
/home/buildroot/buildroot-test/instance-1/output/host/arm-buildroot-linux-uclibcgnueabi/sysroot/usr/lib/libasound.a(rawmidi_symbols.o):(.data+0x4): undefined reference to `_snd_module_rawmidi_virt'

Fixes:

  http://autobuild.buildroot.net/results/5964e7028c31a8f75b38a27270410f0b3c5c8422/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
[Arnout: add upstream link to the patch]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>