sysreset: Add poweroff-gpio driver

Add GPIO poweroff driver, which is based on the Linux
driver and uses the same DT binding.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 70692f0..0e5c7c9 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -43,6 +43,13 @@
 
 endif
 
+config POWEROFF_GPIO
+	bool "Enable support for GPIO poweroff driver"
+	select DM_GPIO
+	help
+	  Support for system poweroff using a GPIO pin. This can be used
+	  for systems having a single GPIO to trigger a system poweroff.
+
 config SYSRESET_GPIO
 	bool "Enable support for GPIO reset driver"
 	select DM_GPIO