reset: Add generic reset driver

This patch adds a generic reset driver. It is designed to be useful when
one has a register in a regmap which contains bits that reset other
devices. I thought this seemed like a very generic use, so here is a
generic driver. The overall structure has been modeled on the syscon-reboot
driver.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 88d3be1..58ba0c6 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -148,4 +148,9 @@
 	help
 	  Support for reset controller on i.MX7/8 SoCs.
 
+config RESET_SYSCON
+	bool "Enable generic syscon reset driver support"
+	depends on DM_RESET
+	help
+	  Support generic syscon mapped register reset devices.
 endmenu