Use stdlib.h defined types uint8_t, uint16_t, uint32_t and uint64_t
for compatibility with musl libc

--- include/pcm.h	2015-02-26 13:34:52.000000000 +0100
+++ include/pcm.h	2015-07-28 13:44:32.423885625 +0200
@@ -29,6 +29,8 @@
 #ifndef __ALSA_PCM_H
 #define __ALSA_PCM_H
 
+#include <stdint.h>	/* uint_ types */
+
 #ifdef __cplusplus
 extern "C" {
 #endif
