dt-bindings: add device tree binding for Allwinner H6 main CCU

dt-bindings: add device tree binding for Allwinner H6 main CCU

[ Upstream commit 2e08e4d2ff488424919d69dd211ac860a019ac1d ]

The Allwinner H6 main CCU uses the internal oscillator of the SoC, which
is different with old SoCs' main CCU.

Add device tree binding for the Allwinner H6 main CCU.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>