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/test/dm/Makefile b/test/dm/Makefile
index 518ee8e..0d1c66f 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -75,4 +75,5 @@
 obj-$(CONFIG_DM_RNG) += rng.o
 obj-$(CONFIG_CLK_K210_SET_RATE) += k210_pll.o
 obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
+obj-$(CONFIG_RESET_SYSCON) += syscon-reset.o
 endif