ARM: dts: turris-omnia: fix hardware buffer management

Hardware buffer management has never worked on the Turris Omnia, as the
required MBus window hadn't been reserved. Fix thusly.

Fixes: 018b88ee ("ARM: dts: turris-omnia: enable HW buffer management")
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Tested-by: Klaus Kudielka <klaus.kudielka@gmail.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm/boot/dts/armada-385-turris-omnia.dts

@@ -32,7 +32,8 @@ soc {
 		ranges = <MBUS_ID(0xf0, 0x01) 0 0xf1000000 0x100000
 			  MBUS_ID(0x01, 0x1d) 0 0xfff00000 0x100000
 			  MBUS_ID(0x09, 0x19) 0 0xf1100000 0x10000
-			  MBUS_ID(0x09, 0x15) 0 0xf1110000 0x10000>;
+			  MBUS_ID(0x09, 0x15) 0 0xf1110000 0x10000
+			  MBUS_ID(0x0c, 0x04) 0 0xf1200000 0x100000>;
 
 		internal-regs {