ASoC: uniphier: change status to orphan

Since I'm leaving from Socionext, I'll unable to access specification
documents of this hardware (these are not public). So change the
state to orphan until someone will maintain this driver.

Signed-off-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>