arm64: dts: imx8mp-beacon-kit: Fix Stereo Audio on WM8962

[ Upstream commit 4e69cd835a2d5c3915838491f59a68ee697a87d0 ]

The L/R clock needs to be controlled by the SAI3 instead of the
CODEC to properly achieve stereo sound. Doing this allows removes
the need for unnecessary clock manipulation to try to get the
CODEC's clock in sync with the SAI3 clock, since the CODEC can cope
with a wide variety of clock inputs.

Fixes: 161af16c ("arm64: dts: imx8mp-beacon-kit: Fix audio_pll2 clock")
Fixes: 69e2f37a

 ("arm64: dts: imx8mp-beacon-kit: Enable WM8962 Audio CODEC")
Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>