sunxi: Use sysreset framework for poweroff/reset

Instead of hardcoding the watchdog for reset, and the PMIC for poweroff,
use the sysreset framework to manage the available poweroff/reset
backends. This allows (as examples) using the PMIC to do a cold reset,
and using a GPIO to power off H3/H5 boards lacking a PMIC. Furthermore,
it removes the need to hardcode watchdog MMIO addresses, since the
sysreset backends can be discovered using the device tree.

Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b4808d4..ae911d6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1084,6 +1084,9 @@
 	imply SPL_MMC if MMC
 	imply SPL_POWER
 	imply SPL_SERIAL
+	imply SYSRESET
+	imply SYSRESET_WATCHDOG
+	imply SYSRESET_WATCHDOG_AUTO
 	imply USB_GADGET
 	imply WDT