arm64: dts: rockchip: add SPDIF node for ROCK Pi 4

stable inclusion
from stable-v5.10.192
commit fba59a4b55ae582b0b2a86cb2f854385c69f2761
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I933RF

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fba59a4b55ae582b0b2a86cb2f854385c69f2761



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[ Upstream commit 697dd494 ]

Add a SPDIF audio-graph-card to ROCK Pi 4 device tree.

It's not enabled by default since all dma channels are used by
the (already) enabled i2s0/1/2 and the pin is muxed with GPIO4_C5
which might be in use already.
If enabled SPDIF_TX will be available at pin #15.

Signed-off-by: Alex Bee <knaerzche@gmail.com>
Link: https://lore.kernel.org/r/20210618181256.27992-6-knaerzche@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Stable-dep-of: cee57275 ("arm64: dts: rockchip: Disable HS400 for eMMC on ROCK Pi 4")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>