Added new ignore patterns

Added ignore patterns for files in the new 'examples' directory.
The file 'audio.raw' is generated by running pcm-writei.
diff --git a/.gitignore b/.gitignore
index 19bc7e4..4bbe27c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,11 @@
 *.so
 *.so.*
 *.a
+
+examples/audio.raw
+examples/pcm-readi
+examples/pcm-writei
+
 utils/tinyplay
 utils/tinycap
 utils/tinymix