clk: sunxi: update clock-output-names dt binding documentation
clk: sunxi: update clock-output-names dt binding documentation

clock-output-names is now required for most of sunxi clock nodes, to
provide the name of the corresponding clock. Add the new requirements,
exceptions, as well as examples.

Signed-off-by: Chen-Yu Tsai <11e8bbde1bc9e0af703df23be02afe58864a4a18@csie.org>
Signed-off-by: Emilio López <86fa523305b8ad6a8a853c04cfef24a0445908d3@elopez.com.ar>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs