The Marvell XSMI controller needs 3 clocks to operate correctly :
 - The MG clock (clk 5)
 - The MG Core clock (clk 6)
 - The GOP clock (clk 18)

 This commit adds them, to avoid system hangs when using these
 interfaces.

[gregory.clement: use the real first commit to fix and add the cc:stable
flag]
Fixes: f66b2aff ("arm64: dts: marvell: add xmdio nodes for 7k/8k")
Cc: <stable@vger.kernel.org>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>