Let pcm_mmap_read/write call pcm_readi/writei

The pcm_readi and pcm_writei also can deal with the mmap read/write.
Also mark the pcm_mmap_read/write functions as deprecated functions and
update the test case.

Add mmap playback support to tinyplay
diff --git a/src/pcm.c b/src/pcm.c
index 3d7da0c..10e477b 100644
--- a/src/pcm.c
+++ b/src/pcm.c
@@ -1547,10 +1547,10 @@
 int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count)
 {
     if ((~pcm->flags) & (PCM_OUT | PCM_MMAP))
-        return -ENOSYS;
+        return -EINVAL;
 
     unsigned int frames = pcm_bytes_to_frames(pcm, count);
-    int res = pcm_mmap_transfer(pcm, (void *) data, frames);
+    int res = pcm_writei(pcm, (void *) data, frames);
 
     if (res < 0) {
         return res;
@@ -1562,10 +1562,10 @@
 int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count)
 {
     if ((~pcm->flags) & (PCM_IN | PCM_MMAP))
-        return -ENOSYS;
+        return -EINVAL;
 
     unsigned int frames = pcm_bytes_to_frames(pcm, count);
-    int res = pcm_mmap_transfer(pcm, data, frames);
+    int res = pcm_readi(pcm, data, frames);
 
     if (res < 0) {
         return res;