sunxi-sound: Merge sun5i sound support into sun4i code

I did a diff between the 2 soc/sound/sun?i dirs, then renamed differently
named files, and s/sun5i/sun4i/ and run the diff again. After this the
differences were very small. This patch adds the differences to the
sun4i code (with machine_sun4i() / machine_sun5i()) checks and drops the
entire sun5i dir.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>