Adding debug macro and cflags of test program

Adding trivial -O2 to test program and setting debug macro for the
driver. Utilize the debug functionality of driver.

Signed-off-by: Chen, Yiqun
Setting up conventional debug information

Toggle all the print functionalities on when the DEBUG macro was
enabled. Avoid any redundant output in release.

Signed-off-by: Chen, Yiqun
Covering test program

The initial version of a sound funcational test program. With some
trials it may cause the fifo the be fulfilled or left empty.

Signed-off-by: Chen, Yiqun