dm: sysreset: add watchdog-reboot driver

Add a new sysreset driver that uses the recently added watchdog support.
It performs a full SoC reset by calling wdt_expire_now op.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index bd352e7..b683811 100644
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -7,6 +7,7 @@
 obj-$(CONFIG_SYSRESET) += sysreset-uclass.o
 obj-$(CONFIG_SYSRESET_PSCI) += sysreset_psci.o
 obj-$(CONFIG_SYSRESET_SYSCON) += sysreset_syscon.o
+obj-$(CONFIG_SYSRESET_WATCHDOG) += sysreset_watchdog.o
 
 ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_ROCKCHIP_RK3036) += sysreset_rk3036.o