Move buildroot to bsp directory.

bsp/buildroot/package/musepack/0004-missing-sys-select.patch

@@ -0,0 +1,21 @@
+Add missing <sys/select.h> include
+
+This header is needed when types like fd_set are used. This fixes a
+build issue occuring on the musl C library.
+
+Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
+[Thomas: better commit log.]
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+
+Index: b/mpcenc/mpcenc.h
+===================================================================
+--- a/mpcenc/mpcenc.h
++++ b/mpcenc/mpcenc.h
+@@ -34,6 +34,7 @@
+ //// portable system includes //////////////////////////////////////
+ #include <stddef.h>
+ #include <math.h>
++#include <sys/select.h>
+ 
+ //// system dependent system includes //////////////////////////////
+ // low level I/O, where are prototypes and constants?