arm: mvebu: system-controller: Rework to use UCLASS_SYSCON

The system-controller driver for 32-bit Armada is currently registered
as UCLASS_RESET, since it only provides enabling/disabling PCIe ports.

Rework it as UCLASS_SYSCON and bind mvebu-reset as a child device.

Signed-off-by: Marek BehĂșn <kabel@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index ef790d9..d44ca3a0 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -28,7 +28,7 @@
 obj-$(CONFIG_ARMADA_XP) += ../../../drivers/ddr/marvell/axp/xor.o
 obj-$(CONFIG_ARMADA_MSYS) += ../../../drivers/ddr/marvell/axp/xor.o
 
-obj-$(CONFIG_DM_RESET) += system-controller.o
+obj-$(CONFIG_ARMADA_32BIT_SYSCON_RESET) += system-controller.o
 
 ifdef CONFIG_ARMADA_38X
 obj-$(CONFIG_MVEBU_EFUSE) += efuse.o